Exchange Server - Email Bounces - 550 Sender verify failed

Mail is being rejected due to a problem on your exchange server.
Your server may still be using the relays.ordb.org RBL, which has been offline for some time.
On March 27, the RBL was brought back online, but it is now rejecting everything.
This is an effort by the operators to get people to remove the dead RBL from their mail server configurations.

The process goes like this:

1. Sample@Sample.com sends a message to a email address on our server.

2. Our server contacts your exchange server to verify that Sample@Sample.com is a real user.

3. Your exchange server rejects the connection because of the relays.ordb.org issue.

4. Our server can't verify that Sample@Sample.com is a legitimate sender, and so it rejects the message.

You will want to contact the administrator of your exchange server and inform them of the relays.ordb.org
issue, and request they trouble shoot your 550 Sender Verify Failed bounce message.

Please let us know if you have any additional questions by opening a ticket here:
http://www.yourtravelcheck.com

Holly Hicks
Director of Web Operations