4.12 I have a static IP, but I'm on a dial-up. My ISP pulls secondary MX for my domain. When I connect I can't seem to get mail. What should I do?

This is a situation where you need ETRN. ETRN is not an acronym like SMTP or POP. It is an SMTP command used by remote hosts to force a server to queue mail to a client. It is defined in RFC 1985: SMTP Service Extension for Remote Message Queue Starting.

This is done with a Perl script or with a bash script. The source code for sendmail includes a copy of etrn.pl but it's not included in the Red Hat Linux binary RPM for sendmail. If you really need it you can get it by downloading the source code for sendmail from sendmail.org or installing the src.rpm and extracting it from there.

You could also use fetchmail to do the same thing. See man fetchmail for more information but essentially to use fetchmail for ETRN your .fetchmailrc would look something like this:

   poll server.uguessit.com proto ETRN

Set the permissions on your .fetchmailrc file to 0710 by issuing the command chmod 0710 .fetchmailrc. Then to run fetchmail run the command like shown below:

   [root@boss /root]# fetchmail -v -S server.uguessit.com
   fetchmail: 5.1.0 querying server.uguessit.com (protocol ETRN) at Sun, 05 Dec 1999 19:54:57 -0500 (EST)
   fetchmail: SMTP< 220 server.uguessit.com ESMTP>
   fetchmail: SMTP< EHLO boss.uguessit.org>
   fetchmail: SMTP< 250-server.uguessit.com
   fetchmail: SMTP< 250-PIPELINING
   fetchmail: SMTP< 250-SIZE 10240000
   fetchmail: SMTP< 250-ETRN
   fetchmail: SMTP< 250 8BITMIME
   fetchmail: ETRN< ETRN ns.uguessit.org
   fetchmail: ETRN< 250 Queuing started
   fetchmail: Queuing for ns.uguessit.org started
   fetchmail: Polling server.uguessit.com
   fetchmail: ETRN< QUIT
   fetchmail: SMTP< 221 Bye
   fetchmail: normal termination, status 0

You could also create a cronjob which would force a connection and an ETRN query at the interval you specify (once an hour for example).