Using ETRN with MailSite The ETRN command can be used to initiate delivery of queued mail. ETRN allows a remote server with intermittent connectivity, such as those using a dialup connection, to obtain mail queued for them by the MailSite Server. The SMTP receiver service at the target mail server must support the ETRN command. Note that the MailSite SMTP Receiver (SMTPRA) service supports this command.

The command-line program MSSTART, which is included with MailSite, allows a remote mail server to connect to MailSite and use the ETRN command to initiate delivery of queued mail.

When a message is received for a remote domain, it is put in the holding and spool\domains folder. MailSite will try to deliver the message according to the elapsed time schedule as defined in the console. The ETRN command can be used to force a retry at that moment in time, rather than waiting for the retry time in the schedule to elapse.

MailSite also supports Authenticated ETRN, which ensures the SMTP client is authenticated (using the AUTH command with a valid mailbox name and password).

Further details on all of the above can be found within the MailSite Help file, by simply searching for "ETRN" If you wish to set-up mail for a certain domain to take a particular route, and the customer to later connect using the ETRN command with a utility such as MSSTART, please follow the instructions below:

1. Open the MailSite console
2. Within Server > Security > Security Properties > Anti Spam > "Accept mail relay for these domains" tab.
3. Add the domain(s) you want to relay to
4. Click "Ok" then "Ok" again
5. Next click Server > Routes
6. Add the domain(s) you specified in the security settings (in step 3) and select the "Force" radio button
7. After you have added the domains, you must double click each instance and specify the IP address of the remote server for the route to be enabled.
8. Be sure to modify the port numbers if your servers are accepting mail through other ports other than the default, which is port 25.
9. Specify the preference of delivery for each. O (zero by default) but you can have 10, 20, etc. the lowest number will always be used first.

When the customer then connects to MailSite using the ETRN command (with the MSSTART utility for example), mail will be delivered to their server.

Should you wish to use Authenticated ETRN, you need create a mailbox within MailSite to allow a user to initiate delivery. An existing account can be used if required. However, it is best to create an account in the default domain, with a name such as "collect". This will ensure that a fully qualified user name does not need to be specified during the authentication process.