Adventures in disaster recovery

Today I found out what happens on a virtual server when the disk space is full and a piece of spam mail arrives.

1. The spam gets filtered to the spam folder
2. The mail cannot be saved, so return to sender
3. The sender is the spam filter, namely me. Send an error message via mail
4. The mail cannot be saved, so return to sender
5. Repeat ad infinitum

At which point I opted to resize my diskspace. 45 minutes later, we were back online.