I have a new install of Exchange 2013, I enabled the anti-spam features. From day one, my server has been sending out NDR spam from "Sender" <> (no sender just the two "<>") to user.ru, user.ro, user.gr, etc.
This issues is driving me crazy and there is almost zero info on the net with this issue. I find it hard to believe a clean install does this right out of the box. In Exchange 2007/10, I just have to tic a box in the transport agent.
Can someone help me please, I'm lost. Hell I even installed GFI this morning just to see if that would make a difference and even GFI is letting the SPAM <> mail through without any issues. It's just a matter of time before my server is blacklisted...
Thanks you,
TCMagic