The memory usage is fine, so is hard drive space.
Did a bit of troubleshooting and I'm a bit closer to the solution.
I noticed that the problem only occurs when a virus was in a email message.
So it had to be related to clamd.
Also I noticed some time ago that there was a permissions difference in my spamsnake after the update and an old backup 'before' update.
The folder /var/spool/MailScanner should have permissions postfix:www-data for all containing folders:
I manually set them correct yesterday. Somehow the folder incoming gets permissions changed to postfix:clamav and then is when the problems arise. The moment a virus message arrives, mailscanner crashes. If i correct the permissions, mailscanner runs without crashing.
So question is, what is causing /var/spool/MailScanner/incoming to change it permissions?
Thx for your insight.