I have an Exchnge 2007 environment with a Barracuda spam box in front. My inside network domain is not the same as the outside domain. It's been working for ages now, but today we start getting lots of undelivered emails - mostly stuff lined up for aol.com and comcast.net. I have been emailing people all day long and suddenly this afternoon I start getting stuff like this:
gvlscsv1.corporate.vox.net #550 5.7.1 Access denied. IP name lookup failed [184.108.40.206] SRC003 Contact firstname.lastname@example.org ##
Original message headers:
Received: from Exchange2.TSGJAX.COM (10.10.x.x) by Exchange1.TSGJAX.COM
(10.10.x,x) with Microsoft SMTP Server (TLS) id 8.1.393.1; Mon, 15 Feb 2010
Received: from Mail7.TSGJAX.COM ([fe80::9516:4bca:64f:b1db]) by
Exchange2.TSGJAX.COM ([10.10.x.x]) with mapi; Mon, 15 Feb 2010 16:58:11
Now the .39 address is my public IP for my front end (CAS/HT) Exchange1 server and I have a reverse DNS entry for mail.stellar.net set up for that IP.