In recent years, email has become an essential business tool, as well as an important means of personal communication. In many business environments, email is one of the primary reasons for networking computers in the first place. This chapter discusses various methods for providing the users of your network with the ability to send and receive email messages over their network connections.

Originally, businesses used email as an internal communications tool with products that designated one or more computers on the network as an email server. Each workstation on the network had an email client program that connected to the server and retrieved the messages intended for a specific user. Because the entire system was internal to the company, the email system did not have to conform to any general standard; as long as clients and servers used the same manufacturer's products, they were able to communicate properly.

Eventually, people began to use online services that offered email, such as CompuServe and MCIMail, for business communications when they discovered that some of their correspondents in other companies used the same service. This type of external email was convenient for users who happened to use the same online service, but communications between services was not available. Later, some of the services began to provide gateways between email systems, but this still did not provide a universal solution that could connect everyone conveniently.

When the popularity of the Internet exploded in the late 1990s, email was revolutionized by the emergence of a standard that could be shared by everyone and that was not controlled by proprietary interests. Internet email provided business users with a common address format and universal connectivity to almost anyone. Just a look at the changes in the business cards of any high-tech company employee can demonstrate the difference that Internet email has made. In 1995, well-connected email users might have had three or four email addresses on their business cards, for the various online services they used to communicate with their correspondents. Now, a typical business card contains only a single Internet email address for use by everyone.

If you connect your network to the Internet, you will almost certainly want to provide your users with email access, but you may find that you can benefit from an internal email system as well. It is possible to build a unified system on your network through which your users can send and receive both Internet and internal email using a single interface.

Email is a classic example of a client/server application. A user at a workstation runs a client program that connects to the email server, downloads all of the waiting messages, and displays them. In the same way, the client program sends outgoing messages to the server, which either holds them until retrieved by the intended recipient or forwards them to another server.

An internal email system requires that you have both the server and client programs running on computers connected to your LAN. For Internet email, your ISP typically provides the server, and the user provides the client software. Windows 98 contains both internal and Internet email client software, as well as a server that you can use to host internal email for your network.

In addition to the software, you must assign each of your users an email address. Internal email systems are proprietary and can use any format. In most cases, the login name that a user employs when connecting to the network also serves as an email address. An Internet email address consists of the familiar user@domain.com format, in which a user name and domain name are separated by an "@" symbol.

Internet email addresses are assigned by the administrator of the email server. An Internet access account with an ISP almost always includes an email address on their server, but depending on the type of account you have and your ISP's policies, you may have to pay extra to get an address for each of your network's users.

In addition to the software included with Windows 98, there are a great many third party email products that you might want to consider. Third party client programs often provide more features than Windows 98's software, and there are also client/server software packages and even hardware devices that provide turnkey email solutions for small networks.

Obviously, in order to use Internet email, a computer must have access to the Internet. If you have installed a shared Internet connection on your network, as outlined in Chapter 10, Accessing the Internet, then providing your users with email access is a matter of providing them with email accounts and a client program.

Internet Email clients require access to two different types of servers, one for incoming and one for outgoing mail. These servers need not be separate computers; many ISPs run both services on one computer. Email clients use SMTP (the Simple Mail Transport Protocol) to send their outgoing mail to an SMTP server, which forwards it to the next server on its journey to the destination. The SMTP protocol also carries the email traffic between servers. Like all Internet protocols, SMTP is part of the TCP/IP suite; it's messages are encapsulated within IP datagrams. To use this, you must have TCP/IP installed on every workstation that will access Internet email.

The SMTP servers rout the traffic across the Internet using the domain name included in the email address (that is, the part of the address following the "@" symbol). Using a DNS request, a server can discover the IP address of the mail server hosting a particular domain and send email traffic to it using standard IP routing. The mail server that hosts the domain then uses a second service to send the email messages to the appropriate clients.

To retrieve its messages, an email client connects to either a POP3 (Post Office Protocol version 3) or IMAP (Internet Message Access Protocol) server. These protocols are similar in function; IMAP provides a few added features, but POP3 is more widely used. Unlike SMTP servers, which immediately forward the mail messages they receive to the next stop on the way to their destinations, POP3 and IMAP servers store the messages they receive until a client retrieves them.

It is on the POP3 or IMAP server that users have their email accounts, identified by the name that appears before the "@" symbol in the email address. This part of the address is not even used until a message arrives at the POP3 or IMAP server for the domain. When email traffic arrives at the domain's mail server, it is put into the appropriate mailbox for the account. Each time that a user logs in with an email client, the server checks his or her mail box and sends the waiting messages to the client, again using the SMTP protocol. The individual email accounts on the POP3 server are password protected, to prevent unauthorized users from accessing other peoples' mail.

The simplest way to obtain SMTP and POP3 or IMAP services for your clients is use your ISP's servers. This means that the ISP will handle all of the administrative tasks like creating the accounts on the POP3 or IMAP server and setting the passwords. If you want to add a new email user to your network, you must contact the ISP to open an additional account on the server.

When you open a standard dial-up account with an ISP, at least one email address is almost always included in the monthly fee. Some ISPs provide multiple addresses with one account, presumably for use by the various members of a family. In most cases, you can purchase additional addresses as needed, for a supplemental monthly fee. Your ISP may also impose limitations on the amount of disk space each account can use on the server, or on the size of files attached to email messages.

Most email clients, by default, instruct the POP3 or IMAP server to delete the email messages once they have been sent to the client. This is intended to prevent the server's disk drives from being overwhelmed by large numbers of permanently-stored messages. Actually, the email messages themselves are plain text and take up very little space. A two or three megabyte size limit on your mailbox will hold a lot of messages, but attached files are another matter. If your users regularly transfer large files using email attachments, you may run into problems both with the server limitations imposed by the ISP and with the file transfers monopolizing the Internet connection. If these attachments are destined for users on the same network, one way of addressing the problem is to use an internal email system that does not transmit the messages through the ISP, as described in "Adding Internal Email," later in this chapter.

The email addresses that the ISP provides for you will be in the ISP's domain. If, for example, your ISP has registered the domain name isp.net, your email addresses will be something like jdoe@isp.net. If you ever change your ISP, your email addresses will change as well.

It is possible to host your own domain, enabling you to create your own permanent email addresses. To do this, you must register a domain name with Network Solutions, Inc. (formerly known as the Internet Network Information Center, or InterNIC) or one of the other companies providing domain registration services. For a small annual fee, you can own the rights to any domain name (such as yourname.com) that has not yet been registered by someone else. You can then create any email addresses you wish within that domain, such as jdoe@yourname.com. When you do this, you can retain your email addresses for as long as you continue to pay the domain registration fee, even if you change ISPs and use different mail servers.

In order to use email addresses in your own domain, however, you must have a POP3 or IMAP mail server to host them. This requires two things:

Every domain on the Internet must have a DNS (the Domain Name System) server that functions as the authoritative source for information about that domain. The DNS server contains resource records, one of which (the MX record) identifies the mail server that hosts the domain. Since DNS servers communicate with each other, any mail server on the Internet can send a request to its local DNS server to determine the IP address of the mail server for a domain.

The POP3 or IMAP server for your domain has the accounts corresponding to the individual email addresses in that domain. Just like your ISP's server, the incoming mail is stored here until clients request it. When someone sends email to an address in your domain, that person's SMTP server issues a request for the IP address of your POP3 or IMAP server that will eventually reach your DNS server. Once the SMTP server knows the IP address of your POP3 or IMAP server, it can send the email message to your server.

Hosting DNS and email servers is well beyond the scope of the typical home or small business network, although it is possible to do it. Windows NT includes a DNS server with the operating system, and although Windows 98 does not, there are third party DNS servers available. There are also a great many SMTP and POP3 server packages available for Windows 98 and Windows NT, some even as reasonably-priced shareware.

The biggest drawback to running these services yourself is not the hardware and software required; it is rather that the DNS and POP3 or IMAP servers must be connected to the Internet at all times in order to be effective. Even if you have a 24-hour Internet connection, such as a dedicated dial-up or a cable modem, there are still going to be times when there are service outages due to technical difficulties, power failures, or other problems. If your DNS and POP3/IMAP servers are not visible to the Internet, then the email directed to your domain will bounce back to the sending server. Many administrators of larger-sized networks do not host their own servers for this reason, even though they have both the expertise and the budget to do so.

As an alternative, there are many companies today that are in the business of hosting web, email, and DNS servers for multiple clients. A good hosting service will have redundant links to the Internet and fault tolerant servers that greatly reduce the chances of your DNS and email servers being offline at any given time. In fact, you may find that your ISP offers these services (for an additional monthly fee). When your servers are off-site, your network can be temporarily disconnected from the Internet and, even though your users will not be able to retrieve their email, the servers will continue to receive and store it until they do.

When someone else hosts your domain, you may or may not have direct access to the server that enables you to create new email accounts yourself. In some cases, you will have to contact the service whenever you want to create or modify accounts. For the average home or small business networker hosting a domain, this is probably a good thing, as it partially relieves the administrative burden.

Windows 98 includes an Internet client called Outlook Express as part of the Internet Explorer 4 package that provides basic email connectivity as well as access to Internet news and directory service servers (see Figure 12-1). You can create folders to store email messages, define rules to process them automatically as they arrive, and maintain an address book of frequent correspondents. There are also a great many other Internet email clients available from third parties that provide a wide range of additional features.

In order to access an account, an Internet email client typically only needs a few basic pieces of information, such as:

Outlook Express uses the Internet Connection Wizard (accessed by selecting Accounts from the Tools menu, clicking the Add button, and choosing Mail) to gather the information needed to create an account and supports the use of multiple accounts. If you receive mail from two different servers, you can have them both downloaded to the same client and displayed in the same interface. Most Internet email clients have a feature that automatically checks for mail using a time interval that you specify. Outlook Express enables you to specify how the client should connect to the Internet, as well as which accounts you want the client to check during these events.

When you use an individual dial-up connection for a computer, you can configure Outlook Express to use a specific Dial-up Networking profile to connect to your ISP whenever it's time to check your email. The system dials in to the ISP, checks for mail, downloads any that it finds, and then hangs up. When the computer uses a shared connection to reach the Internet, you configure Outlook Express to use the LAN connection when communicating with the mail server. If you have a 24-hour Internet connection, the client will simply send messages to the mail servers as needed. If you use a shared dial-up connection for Internet access, the messages to the email servers will trigger the router's dial-on-demand feature, if there is one. Otherwise, the email requests will fail whenever the network is not connected to the Internet.

By default, Outlook Express deletes email messages from the POP3 or IMAP server as it downloads them. You can modify this behavior, however, by leaving the messages intact on the server, deleting them after a specific number of days, or by deleting them when you delete the messages in the client program. This function is most useful when you use more than one computer to check a single email account. If, for example, you normally access your email from your office computer, but occasionally check it from home also, you can configure your client at home to leave the messages intact, so that you will see them again at the office the next day.

Configuring Outlook Express to send and receive Internet email is a relatively simple task, but it is one that you (or your users) will have to perform on each individual machine. The greatest advantages of Outlook Express are that it's free and included with Windows 98, as well as with all Internet Explorer 4 and 5 releases. You might want to investigate some of the other email clients on the market , to see if they have features that better suit your needs, such as rules for managing incoming mail and mailing lists.

An internal email system differs from Internet email in two ways:

As the name implies, internal email is a system that is limited to use on your LAN. You may question why such a thing is even necessary on a small network, especially when Internet email provides communications between users on the LAN as well as users elsewhere on the Internet.

When you use an ISP's servers to process your network's email communications, all of the traffic naturally has to pass over the Internet connection to get to those servers. If one user on your network sends an Internet email message to another user on the same network, that message has to travel over the dial-up (or other) connection to the SMTP server and eventually find its way to the POP3 or IMAP server, from which the recipient's client program retrieves it, transmitting the same message again over the Internet connection. This is an unnecessary expenditure of bandwidth that can cost you money if you use dial-on-demand to connect to the Internet.

The problem worsens if the email message contains attached files. In a case like this, the file is transmitted across the Internet connection twice, once to the SMTP server and once from the POP3 or IMAP server to the receiving client. If you use a shared, dedicated dial-up connection to the Internet, a one megabyte file attached to an email message addressed to another network user can monopolize the connection for up to 20 minutes or more, preventing other users from doing their work.

In addition, depending on your ISP's network configuration, you may be amazed to find out that an Internet email message can sometimes travel through servers hundreds or thousands of miles away in order to reach a recipient in the next room. Clearly, an internal solution provides a better and faster route between these two points.

The process of installing an internal email system on your Windows 98 network consists of the following basic steps:

As with Internet email, an internal email system requires clients and servers. However, since the entire system will be located on your LAN, you must install and maintain all of the components yourself. Many of the internal email products on the market, such as Microsoft Exchange and Lotus Notes, are intended for use on medium- to large-sized networks, and are far too complex and resource intensive for use in a home or small business. The Windows Messaging components included with Windows 98 (formerly known as Microsoft Mail) are perfect for use on a small network. If you do not intend to use Internet email, you can still exchange messages and files with other users on your network. If you plan to use Internet email as well, you can use a client like Microsoft Outlook 97, that is capable of sending and receiving both Windows Messaging and Internet email messages.

Windows Messaging was not originally intended to be a part of Windows 98, although it was included with Windows 95 and, as Microsoft Mail, with Windows for Workgroups. Apparently, Microsoft assumed that users of internal email would be running Microsoft Exchange, which includes a client that is virtually identical to the Windows Messaging client. The components are not installed with the operating system, nor can you install them from the Add/Remove Programs Control Panel. In fact, Windows Messaging was included on the Windows 98 CD-ROM as an afterthought, in response to beta testers that lamented its omission. The software is all but identical to the versions included with Windows 95, and contains no new features.

To install Windows Messaging on a Windows 98 system, you must execute the Wms.exe file from the \tools\oldwin95\message\us directory on the Windows 98 CD-ROM. This installs two components:

A Microsoft Mail post office is the functional equivalent of an Internet email server, except that it is designed to support only a relatively small number of users on a local network. Unlike Internet email, separate servers are not needed for the transmission and reception of messages, nor is there any communication possible between servers. The post office is simply a repository for user accounts containing messages waiting to be retrieved by clients.

When you open the Microsoft Mail Postoffice Control Panel, you are given the choice of administering an existing post office or creating a new one. When you create a new post office, you must specify a location directory for it, and a user name and password for the account that you will use to administer it. In the directory you specify, the program creates a post office directory called \wgpo0000. You must share this directory and grant your users full access to it in order for Windows Messaging clients to access their email. To simplify the client configuration process, it is a good idea to create a new share out of the post office directory created by the installation program and give it an obviously descriptive name, such as Post Office.

Once you create the post office, the only maintenance that is required is to create accounts for all of the users on your network. In order to administer an existing post office, you identify its location and supply the account name and password you specified when creating it. Then, from the Post Office Manager dialog box (see Figure 12-2), you can manage the properties of existing accounts and create new ones.

Each account has its own dialog box (see Figure 12-3) in which you can store basic contact information about the user, as well as the account name (which functions as the email address) and the password to the account.

The Microsoft Mail post office is not very complicated, nor is it very secure. It is designed to provide only the most basic email functionality for a small network, but it is a perfectly viable solution for home and small business users that want to exchange messages and files.

Because it runs on one of your workstations, the post office can conceivably degrade the performance of the other programs running on the computer. The amount of degradation depends on the number of users and amount of mail they send and receive, but it is usually not serious. However, the post office must be running at all times in order for the email system to be reliable. If a person using the post office machine as a workstation runs a program that hangs the system, or has to reboot for any other reason, the mail service is interrupted. A reboot during a mail transfer, such as a message with a large file attached, can even corrupt the data and cause problems with the user's mailbox files.

If you will be running a small business network that relies on email, you might want to consider running a computer as a dedicated post office, for these reasons. This may seem excessive, but a mail server of this type does not require a state-of-the-art computer. Even an old 386 running Windows for Workgroups will serve adequately, since the Microsoft Mail post office in that operating system is compatible with the Windows Messaging client in Windows 98.

Installing Windows Messaging on Windows 98 provides the operating system with support for MAPI, the Messaging Application Programming Interface. MAPI is a standardized interface that provides messaging services to any client designed to make use of them. Windows Messaging itself includes a client program, but you can also install other clients, like Microsoft Outlook 97, that provide additional features. For example, the Windows Messaging client provides internal email capabilities, a personal address book, and faxing (if you install the additional Microsoft Fax module in Windows 98). Outlook 97 can make use of these same services, and adds others of its own, including Internet email.

The first time that you activate the Windows Messaging client, by clicking the Inbox icon on the desktop or by selecting Windows Messaging from the Programs group on the Start Menu, the program launches the Inbox Setup Wizard and selects the Microsoft Mail service by default. To set up the mail service, you must specify the location of the post office that the system will use. You can type a path or browse to the appropriate share, but whichever method you choose, it is best to specify a UNC path name, instead of a drive letter. This is because the drive letters assigned to network shares can change, but UNC paths are permanent (unless you modify the share). If you choose to browse to the location of the post office, open the Network Neighborhood and select the appropriate share. This will supply the UNC name of the share to the field. Otherwise, you can supply the share name using the standard UNC \\server\share notation.

Once the wizard connects to the post office, you select the mailbox you want to connect to from a list of the accounts that have already been created by the post office administrator (see Figure 12-4). After selecting an account and supplying the appropriate password, the wizard prompts you for a location for the user’s personal address book. This is a file with a .pab extension that will hold the addresses of other users. This feature is of limited value for internal email users, since the post office address book is always available, but when using the MAPI client for Internet email, this is where the contact information for other users is stored. The wizard then prompts for the location of a personal folders file, which is a file with a .pst extension that contains the email messages received by the client. The user can create a hierarchy of folders and subfolders to categorize the incoming messages and save them for future reference. By default, these files are called Mailbox.pab and Mailbox.pst, and are created in a directory called C:\Exchange.

At this point, the configuration process is completed, and Windows Messaging displays the main Inbox interface, as shown in Figure 12-5.

Even though only one post office is required for the network, Windows Messaging must be installed and configured on each computer that will use the internal email system, either by the user or the network administrator.

Once the Inbox Setup Wizard has configured the Microsoft Mail service, it is possible to modify the configuration of the client by selecting Services from the Tools menu in Windows Messaging. The Services dialog box lists the three services that the wizard configured during the installation:

By modifying the properties of these services, you can control the behavior of the client.

Once the Windows Messaging client has been configured, it will connect to the post office automatically every time the user opens the Inbox, using the mailbox name and password you supplied. However, you can change this information in the Properties dialog box for Microsoft Mail, shown in Figure 12-6.

If you ever move the post office to another computer, you can modify the path to the post office on the Connection page. The Logon page contains the name of the mailbox and the accompanying password to use when connecting to the post office. By default, a checkbox on this page labeled When Logging On, Automatically Enter Password is enabled. This causes the client to automatically log on to the post office and check for new mail whenever anyone opens Windows Messaging on the computer.

If you clear this checkbox, Windows Messaging will present the dialog box shown in Figure 12-7 every time a user launches the program. This provides a measure of security by forcing users to enter their passwords, and also enables users to log on to the post office using different mailboxes and passwords, or even to log on to a different post office.

Windows Messaging is not directly supported by Windows 98 user profiles. In other words, if you configure a computer with user profiles to support individualized desktops, menus, and other elements for multiple users, launching Windows Messaging will cause the program to log on to the post office using the account information you supplied when you first installed it. Clearing the When Logging On, Automatically Enter Password checkbox to force each of the users to log on to the post office with their own account is only one element in providing multiple user support.

Logging on to the post office using a different account will cause the Windows Messaging client to access the other user’s mail, but it will still store that mail in the original user’s personal folders file on the workstation. In order to create separate storage areas for each user on the local system, you must create a new Personal Folders service for each user. Before you do this, you must create profiles for each of your users (using the Windows 98 Users Control Panel) and install and configure Windows Messaging in the usual manner. Each user should also already have a mailbox account in the post office.

To create new personal folders for a user, you log on to Windows 98 with that user’s logon name, causing the system to load the appropriate profile. When you launch Windows Messaging, log on to the post office with that users mailbox name and password. At this point, the client will be ready to receive the new user’s mail but will be displaying the original user’s personal folders. In the Services dialog box, remove the Personal Folders service from the list and add it again, this time specifying a different directory or file name for the personal folders file. The program will create the new file and associate it with the user profile currently loaded. Whenever that user logs in, the Windows Messaging client will load the correct personal folders file.

You can use this same procedure to create a new Personal Address Book file for users as well, or to move a user’s folders and address book to another computer. When you create a Personal Folders or Personal Address Book service, you can specify the name of an existing .pst or .pab file anywhere on the network, thus enabling users to access their mail from any machine. Note, however, that creating individual folders and address book files like this does not eliminate the need for the user to log on to the post office manually each time he or she starts the Windows Messaging client. The user profile stores the file locations for each user, but not the mailbox name and password. Therefore, the When Logging On, Automatically Enter Password checkbox must remain cleared for this technique to work properly.

Although the internal email system provided by Windows messaging is a useful tool for conserving Internet connection bandwidth and providing rapid intranetwork communications, it can be inconvenient to users due to the fact that two separate clients: Windows Messaging and Outlook Express, are required. Outlook 97 is an email, group scheduling, and personal information management application included as part of the Microsoft Office 97 product. While it uses the same MAPI subsystem as Windows Messaging, Outlook 97 provides additional services, including Internet email. On a network that is using both internal and Internet email, Outlook 97 enables users to access all of their mail servers through a single application.

Once you have installed Outlook 97 as part of Microsoft Office, you can use it immediately, instead of the Windows Messaging email client, as Outlook 97 uses the same services. When you select Services from the Tools menu, you see the same services dialog box as in Windows Messaging, with the same services installed. This is because the services are provided by the MAPI subsystem, instead of by the client itself.

The difference in Outlook 97's email support is evident when you click the Add button in the Services dialog box (see Figure 12-8). You will notice that there is now an Internet Email service that you can add to the configuration (among others). When you do this, the program displays a dialog box containing configuration parameters nearly identical to those provided by Outlook Express. You must supply the names of your SMTP and POP3 or IMAP servers and the account name and password that you will use to access the POP3/IMAP server.

When you configure Outlook 97 with both the Microsoft Mail and Internet Email services, messages from both services will arrive in the same Inbox and be stored in the same Personal Folders file. When you create outgoing mail messages, you can choose an internal recipient from the Postoffice Address List or an Internet user from your Personal Address Book.

Several hardware and software manufacturers are beginning to address the growing home and small business network, among them Intel, which has released a line of small InBusiness servers that provide turnkey Internet solutions. The InBusiness Email Station is a self-contained email server that connects to a small network and provides Internet email functions that would otherwise require at least a Windows NT server with additional mail server software. The device connects to the Internet using either a modem (not included) that is attached to the unit or a router elsewhere on the network. Configuring clients to use the email station is no different from configuring them to use your ISP's mail servers. You can use Outlook Express (which is included with the device), Outlook 97, or any other Internet email client.

The email station is a self-contained unit that provides SMTP and POP3 services to network users. In fact, the device is actually a small computer; it contains at least a 2 gigabyte hard drive, has its own IP address, Ethernet interface, and a serial port for connecting to a modem. The device costs anywhere from $650 to $875, which represents a significant investment for a home or small business, so the question should be raised of whether such a thing is really necessary for the average network. The answer is yes, but only under certain conditions. The email station can run in three different modes, each of which has different requirements and serves a different type of environment. These modes are:

And are described in the following sections.

In this mode, the email station functions as the sole mail server for a domain, receiving mail from the Internet using the SMTP protocol and holding it until requested by POP3 clients on the local network. To use this method, you must have the following:

In this mode, the email station is functionally the same as any of the other email servers on the Internet. Any mail addressed to your registered domain is routed to the email station using the IP address in the DNS record. You are responsible for creating the mailbox accounts on the device, so that the incoming mail can be distributed to the appropriate users. If the email station or the Internet connection is down, then the email messages destined for your domain will be lost.

The advantage to this method is that you have complete control of the mail server and its accounts and, because it's on the local network, clients are able to retrieve their mail very quickly. The drawbacks are that the server must remain connected to the Internet at all times in order to be able to receive mail. You must pay for a 24-hour Internet connection and risk losing mail if there is any down time.

In addition, the email station must have a registered IP address, which is not possible if you use a product like NAT32 to route Internet traffic to your network. Registered IP addresses are also visible to other machines on the Internet, leaving them open to intrusion. For example, someone discovering the existence of your SMTP service on the Internet might use it to send "spam" email to thousands of addresses, monopolizing your server and your connection. Other types of intrusions can be more damaging. For the typical home or small business network, the risks and expenses of this method are simply not necessary.

In this mode, the email station retrieves the mail for a domain from your ISP's email server using the POP3 protocol and stores it until it is requested by individual clients. This method requires the following:

The advantages of this method are that the domain is actually serviced by your ISP's mail server. This is the server listed in the DNS record for the domain, so all mail originating from the Internet goes there first. As a result, your ISP is responsible for server security and fault tolerance and you do not need a full-time Internet connection or a registered IP address for the server.

At pre-determined intervals, the email station connects to your ISP's POP3 server, downloads all of the mail for the domain, and transmits all outgoing mail. You must arrange with the ISP to have the messages for all of the email addresses in the domain put into one mailbox. You control the individual mailbox accounts on the email station, which separates the messages by address and places them in the appropriate boxes.

Since the ISP's mail server is always available to receive mail for your domain, there is no need for your server to remain continuously connected to the Internet. With this arrangement, you can use a standard, inexpensive dial-up account to connect to your ISP every 60 minutes during business hours (for example), download the mail, and hang up. The mail is then stored on the email station's hard drive until your network clients retrieve it. In the same way, outgoing mail is stored on the device until the next time it connects. If you're running a small business and you want to provide your users with email only, this can be a better solution than giving them individual ISP accounts or maintaining a full-time connection.

This method requires neither a domain name nor a full-time Internet connection. Each of your users has an individual account on your ISP's POP3 server, and the email station simply accesses all of the accounts at regular intervals and downloads the waiting mail. The advantage here, as with the previous method, is that you control the connection to the Internet. Users can retrieve their mail from the email station at any time, without triggering a connection.

The disadvantage here is that you must have your ISP create a separate email account for each of your users. Many ISPs charge an additional monthly fee for each extra email address, which can add to the overall cost of the solution.

One of the big advantages of the email station, in all modes, is that mail destined for other users on the local network is not forwarded to the Internet. This means that your users have internal email capabilities at all times, without waiting for the server to connect to the ISP. Even if your Internet connection is not functioning, the email station continues to provide local service. This form of internal email also eliminates the need for separate internal and Internet address books. To send a message to a user on the local network, you use the same Internet domain email address that you would use if they were located at another site.

The InBusiness Email Station contains a built-in web server that enables you to configure its properties using any web browser, as shown in Figure 12-9. Through this interface, you can create and manage mailbox accounts and specify how and when the device should connect to the Internet. The device also includes DHCP and DNS server capabilities.

Devices like this are not suitable for every small network. However, if you want to register your own domain name for use with Internet email, a turnkey solution like the InBusiness Email Station can help to reduce your monthly expenses by eliminating the need for a full-time Internet connection and ISP-managed email addresses.