A few nights ago I shut down the VM that my qmailtoaster runs on, bumped the memory up to 4g, and restarted it. First reboot in a long while, so I was nervous. Everything seemed fine.
The next day I noticed that there were a couple of emails I had deleted that had re-appeared. I'd delete them again, and they'd come back again. My mail client shows date sent and date received, and they were definitely all the same sender time. Checking the logs, I see the same set of email being re-accepted in /var/log/qmail/smtp/current over and over. Finally I have a clue. Gmail sent me a delivery warning about one of the emails, as it was a test message from myself, and it says my server is responding with error: 421 Timeout. Talk faster next time. So it seems the email is getting accepted, but then the sending server is given an error 421, so it queues it up for re-delivery. Any suggestions on what I should be looking at to figure this out? -Chris