Do spamassassin or sa-learn understand compressed files or compressed Maildir?
I've been running spamassassin on my ubuntu mail server for years very successfully. Recently, I've been experiencing a lot of difficulty and I'm trying to figure it out. Earlier this year we upgraded the server from Trusty Tahr to Xenial (long time coming!) and some other stuff got upgraded as well. We run an IMAP server with Dovecot against a Maildir formatted message store. I noticed the message store was taking a fair amount of space, so I decided to compress it with zlib (gz compression). Pretty much since the upgrade (and simultaneous switch to compressed Maildir) spamassassin has been doing a much worse job. I upgraded from the distribution version of spamassassin (3.4.2) to the most recent version (3.4.6) but no real joy. I keep a 'learn spam' folder to put false negatives in (stuff that makes it into my inbox which ought not to), and every night, run sa-learn on it and also spamassassin -r to report it. I started noticing that DCC was complaining on report that "missing message body; fatal error". I ran spamassassin -d -r to see what was happening and noticed that it interacted with dcc using dccproc. Maybe dccproc doesn't understand compressed mail? Well, if it doesn't then perhaps sa-learn doesn't either. That might explain why my bayes rules don't seem to be working very well despite retraining. -CJ
