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

Check, if senderreputation is set (get-senderreputationconfig) Set-SenderReputationConfig -Enabled $true Regards from ExchangeOnline | Windows Administrator's Area

Well that did not fix the problem. My server is still sending spam. Here's what one of the messages look like (I removed my actual domain): Identity: mail\71\627065225217 Subject: Undeliverable: Never lose a food storage container again Internet Message ID: <eca63aee-7c00-4c7e-9304-a0fdf7cc7194@mail.mydomain.local> From Address: <> Status: Ready Size (KB): 212 Message Source Name: DSN Source IP: 255.255.255.255 SCL: -1 Date Received: 4/13/2013 1:00:13 PM Expiration Time: 4/15/2013 1:00:13 PM Last Error: Queue ID: mail\71 Recipients: makiyivka@oxickerm.info;2;2;;0;CN=InternetConnector,CN=Connections,CN=Exchange Routing Group (DWBGZMFD01QNBJR),CN=Routing Groups,CN=Exchange Administrative Group As I look at this the SCL rating is -1 so the server thinks is good mail. Can someone help me here? Thank you

Hello, Is your server an open relay? Thanks,Simon Wu TechNet Community Support

Wow. No it is not an open relay. It passes all connection test from https://www.testexchangeconnectivity.com/ I fixed this issue myself. I spent many hours looking for a fix and came on the answer just by studying the "Get-SenderReputationConfig" setting. It was there all along and should be a default setting in Exchange 2013. I'm guessing MS wants to sell their "Exchange Online Protection" so most settings for spam are off by default (and the key to all of this is not just turning them all "on"). the key is making sure they are set for "Outside" as well as "inside". The user is "<>" (inside). I'm very surprised this post has not had a million hits. Thank you,