[Dovecot] Dovecot2 Antispam plugin questions

[Steve Fatula]

Tried to find some doc on this (other than the c code), couldn't, so, asking. I do almost every programming language, except C!

When using DSPAM backend with this tool, will the plugin send ONLY the signature and not the entire message to dspam for retraining? Concerned about very large emails. If this is the case, I'd rather do this than use say the mailtrain backend which I presume would send the entire message. 

Having some permission problems though with the dspam binary since regular users can't execute dspam the way it is currently set up. Any security reason to not allow regular users to run the binary?
 
Steve