SymptomsThe following error appears in the mail log when a message with a big attachment is received:
Dec 30 10:26:29 plesk spamc: skipped message, greater than max message size (256000 bytes)
What is the cause of this error?
ResolutionThis is a restriction of SpamAssassin; it does not check messages with attachments larger than 256KB. This value provides normal server loading.
The spamassassin service consists of perl modules; they may place a heavy load on the server while processing big messages.
Since version 9.0.0, Parallels Plesk Panel reports the error. Messages greater than 256KB in size are not processed by spamassassin. This does not affect the delivery of any other mail.
It is possible to define the "max letter size to filter" parameter in Parallels Plesk Panel versions 7.x and 8.4.
Refer to this article for details: http://kb.sp.parallels.com/945
In plesk 11.5.30 there is an option to configure max mail size for Spamassassin. You should modify parameter SA_MAX_MAIL_SIZE in /etc/psa/psa.conf :
# SpamAssassin max mail size (in bytes)