Setting up a Dial-up Internet Connection

IMail Server is designed to work on a 7-day, 24-hour Internet Connection, but you can also set up IMail Server to support dial-up connections. You can create a dial-up Internet connection from IMail Server to your Internet Service Provider (ISP), allowing you to receive mail from an account with your ISP.

IMail Server does not perform dial-up functions or spawn off dialing commands. To start your RAS/PPP connection to your ISP, you need to either use a scheduling program or start the connection manually.

IMail Server uses the TCP/IP transport on Windows; it does not configure the Windows TCP/IP transport. If you need to set up a RAS/PPP connection, refer to your Windows Help.

Receiving Mail from an Internet Service Provider

When you use a dial-up connection, your inbound mail from the Internet must be stored somewhere, usually with your ISP. Your ISP can store your mail in several ways. Three of the more popular ways are:

• Method 1: The ISP sets up individual mail accounts on the ISP computers. This method usually uses the POP3 mail protocol to read or retrieve mail. Each user dials up the ISP and either reads or downloads mail.
• Method 2: The ISP sets up individual mail accounts on the ISP computers, but the ISP forwards all mail for your users to your mail server when your dial-up connection is up. This method uses the ISP's Internet domain name. Example.
• Method 3: You have a registered Internet domain of your own, and you register your domain to point to the ISP computer. Your ISP stores incoming mail and forwards it to your mail server when your dial-up connection is up. Example.

To register your own domain, contact your ISP. In most cases, they will do the work for you. All you have to do is come up with a name.

If you currently use Method 1, then you must change to either Method 2 or 3 to receive mail from your ISP. IMail Server cannot log into individual mail accounts on your ISP mail server, retrieve the mail, and then parse the mail correctly.

Setting Up the Server for Dial-up Access

1. Setting up IMail Server using a dial-up connection is the same for both Methods 2 and 3, above. To do this, you need to create mail accounts for users on the IMail Server computer. For more information, see Administering IMail Users. If you use Method 2, user names must be the same on both the ISP's computer and your IMail Server computer.
2. Tell Windows about your email domain name. When Windows looks up a domain name, it first searches the \winnt\system32\drivers\hosts file. If there is no match, it asks a Domain Name Server (DNS) for the IP address for the domain name.

   This creates a problem, as your Windows computer has a different IP address than your ISP's computer. When IMail Server looks at the incoming mail, it looks up the domain name to which the email is addressed. If the domain name points to your ISP's computer (your ISP's IP address), then IMail Server sends the mail back to your ISP's computer (which it thinks is correct). Mail will be bounced back and forth until one of the computers sends the message back to the original sender.

   To avoid this problem, set up the domain as a virtual host , then add the domain name to which your incoming mail is addressed -- either your ISP's (Method 2, see Example), or your own (Method 3, see Example) on the Add New Domain page. See Adding a New IMail Domain, Setting Up a Virtual IMail Domain With an IP Address, or Setting Up a Virtual IMail Domain Without an IP Address for more information.

3. Unless you plan on maintaining a 24-hour, 7-day a week dial-up Internet connection, your ISP must spool all mail for your company. Then, have your ISP set up their computer to try to periodically send mail to the IMail Server computer. How often the ISP attempts to send mail to your server depends on how often your dial-up connection is up. Consider the following factors in determining queue times. The first factor is the most important.
   • How long will your dial-up connection last (10, 20, 30 minutes)?
   • How often will your ISP's computer try to send the spooled mail to your computer?
   • How often will your computer try to send mail to the Internet?
   • How much mail will you receive and send when you make your dial-up connection?

For example, if the connection time will be 20 minutes, and you will have relatively light traffic (50 received and 50 sent) and relatively short messages (no attachments or large files) you could set up the queue times as follows:

Queue Time	Minutes
Connection Time	20
ISP Queue Time	15
IMail Server Queue Time	15
Email Quantity	50 received/50 sent (short messages)

In this example, the Connection Time is the amount of time your IMail Server is connected to the ISP's computer. This would be set in your scheduling program. The ISP Queue Time determines how often the ISP mail computer tries to send mail to the IMail Server. The IMail Server Queue Time determines how often IMail Server tries to send mail to the ISP or Internet (this is set up on the SMTP Options page).

To be sure your mail gets processed, regardless of the connection time, make the queue times less than the connection time. If you expect to receive or send greater numbers of messages, or more lengthy mail than in the example, you can either increase the connection time, or decrease both queue times.

Alternatively, you can use the ETRN command to manually retrieve mail from the ISP's mail server. See Using ETRN to Retrieve Mail on a Dial-up Connection.