SMTP Configuration

SMTP Configuration defines the settings for the SMTP protocol which is used by CMail Server to send email.

All email servers use the SMTP (Simple Mail Transport Protocol) to send  Internet mail. To send mail from CMail Server to the Internet, you will need the hostname of your Internet Service Providers SMTP mail server. This information can be obtained your ISP's Technical Helpdesk.

CMail can use one of two methods for sending mail to the Internet. The first and easiest is to specify an upstream SMTP server, usually your Internet Service Provider's mail server. Once the ISP's mail server has taken delivery, it will handle the workload to get the message from A to B. The other method is to use MX resolution where CMail performs lookups to locate the position of the server on the Internet that handles the email for the person you are attempting to send the message to. Delivery by MX resolution can be slow as CMail attempts to communicate with the recipients email server directly but MX does provide ISP independence. See Advanced SMTP Configuration for MX Resolution Configuration.

Specifying an Upstream SMTP Mail Server

  1. Select SMTP Configuration from the Configuration menu.
  2. Enter the name of your Internet Service Provider's SMTP mail server in the SMTP Host field.
  3. Ensure that the Port Number reads 25.
  4. Press OK to exit SMTP configuration and then click File > Save Settings to write the changes you have made to disk.

Other Options on the SMTP Configuration Menu

Kick SMTP Server
As well as sending mail, the SMTP protocol can also be used to collect email from the Internet. One of the problems with SMTP mail collection is that mail is never actually 'collected' from another mail server, it is forwarded on automatically by the remote mail server. This means that if CMail is not online or connected to the Internet when the remote mail server attempts to send mail, the mail is recycled in the remote servers mail queue and then another attempt to made to re-send the mail at a later time. This can be a problem if CMail connects to the Internet only once an hour to exchange mail as it can miss the transfer point.

To counteract this problem, some mail servers will listen on a given port for kick requests and when one is received, will forward all of the mail its queue to the server making the kick request.

To enable this feature, check the Kick SMTP server on connection to the Internet checkbox. Note: This feature is not widely supported. Leave this option Unchecked unless you know for sure that your ISP supports Kick Server.

Trigger Port 
Sets the port upon which CMail will attempt to kick a remote SMTP server. The default is port 79.

Validation
When Validation is turned on, all messages received via the SMTP protocol will be checked to ensure that the message headers and format are not corrupt. Corrupt mail will be removed from the server automatically. This feature is enabled by default and should only be turned off for troubleshooting.

Advanced SMTP Configuration
Configuration Menu
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