We currently have a number of external relay servers that perform virus and spam checking for Zimbra. Zimbra receives messages with standard spamassassin markup and files them into /Junk if it's determined to be spam.
Our problem is that Zimbra seems to make its own determination as to whether or not a message is spam, despite the fact that anti-spam is disabled in Zimbra. If a message comes in with "X-Spam-Status: NO", Zimbra may still put it into the Junk folder.
$ zmprov gacf | egrep -i 'spamheader|spamcheck'
Yet a message with this header was placed into a user's /Junk folder by zmmailboxd:
X-Spam-Status: NO, hits=3.20 required=4.90
Here's the log entry (sanitized):
2010-05-26 11:13:32,515 INFO [LmtpServer-59120] [ip=141.142.2.xxx;] lmtp - Delivering message: size=59163 bytes, nrcpts=1, email@example.com, msgid=<firstname.lastname@example.org m>
2010-05-26 11:13:32,517 INFO [LmtpServer-59120] [email@example.com;mid=98;ip=141.142.2.xxx ;] mailop - Adding Message: id=258931, Message-ID=<firstname.lastname@example.org>, parentId=-1, folderId=4, folderName=Junk.
The message did *NOT* have an X-Spam-Flag: header (it's only added if the message is determined to be spam). There are no filters on the account that could put it into /Junk.
How can we tell Zimbra to not do any kind of local spam filtering and only put things in /Junk if a zimbraSpamHeader value is matched?