If you set up a POP account inside an IMAP account, and have that POP download its messages to a designated folder other than the inbox, does Zimbra run the spam filters against that folder?
I have set up a couple like this, and I see no spam tags in the headers, nor does any filtering seem to be happening to the messages. When I forward the same message to my regular Zimbra account it gets tags, though not tags that result in exclusion. . .I can't tell if this is because my own POP account is whitelisted (I wouldn't think so) or because the spam filter isn't catching all those "postcard.com" messages that are actually hyperlinks to a virus.