What should be listening on tcp port 12345?

[Andreas Winkelmann]

> I'm in the process of adding another front end server to our cyrus email
> cluster.  The new server is running RedHat ES5, and rpm shows the
> version of cyrus is cyrus-imapd-2.3.7.  Our front ends provide imaps,
> smtp (via sendmail) and lmtp.  Sendmail uses smmap to verify the
> recipients addrsess, using the process outlined within the RTCyrus3
> project.  lmtp then handles the delivery of the email to our backend
> servers.  The backend servers are running cyrus-imapd-2.2.12.
>
> During testing of the new server, I noticed a significant delay during
> the delivery of email of up to 10 minutes.  The delay seems to be caused
> by the smmap process while it attempts to connect to tcp port 12345 on
> the backend server.  iptables on the backend server was configured to
> ignore attempts to connect on tcp port 12345.  Changing iptables to
> reject  connections to tcp port 12345 sped up the process considerably.
>
> What process is supposed to be listening on that port?

smmapd. It needs to check for Quota infos on the Backend. At least this is
noted in the Sourcecode of smmapd.

Unfortunately the Port is hardcoded.

> Here's output from /var/log/maillog.  mailstore03 is the correct backend
> server for my mailbox.
>
> Mar 24 14:41:25 postoffice04 smmapd[31605]: executed
> Mar 24 14:42:41 postoffice04 smmapd[31605]: accepted connection
> Mar 24 14:42:41 postoffice04 smmapd[31605]: verify_user(user.rspell)
> proxying to host mailstore03.bates.edu
> Mar 24 14:42:41 postoffice04 smmapd[31605]: verify_user(user.rspell)
> failed: can't connect to mailstore03.bates.edu

--
Andreas