Just a follow up.

After some more hours of debugging, I found these links:
http://www.zimbra.com/forums/administrators/60244-mail-being-virus-scanned-twice-2.html
Bug 79585 – Antivirus...

Hello,

I have this problem with a new installation of Zimbra, that I am trying to solve for the last days, without success.
Everything is running smoothly, except for one thing: the accounts that...