Never a Clean Transition
Monday, April 10, 2006, at 08:04AM
By Eric Richardson
We're moving email service here at the office, from ISP hosted mail to our colocated server. Friday I set up the new accounts and around 5:30 or so I switched MX to point to the new address.
That meant that I knew all weekend there were going to be issues when I walked in the door today.
It's a fact of life: you move services between disparate hosts and something's not going to work right.
In my case I found two issues:
I'm using qpsmtpd as my SMTP server, and all my test messages had been small. Because of that, I didn't know my spool dir was set up incorrectly and was unwritable by the mail daemon.
courier-imap defaults to setting MAXPERIP to 4 connections per IP address. When everyone fired up email this morning errors started popping up and nothing showed in the logs. Once I figured out what was up (though really I didn't... pcg quessed it) it was an easy change.
So after a bit of a hairy morning I think everything's running smooth now.