Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

We send outgoing e-mail with one server relaying e-mail through another server. When e-mail is getting black-listed, is it the originating server that is being blacklisted or the relay?

share|improve this question
up vote 1 down vote accepted

You are going to be black-listing the IP on a specific host, right? You want to find the received header corresponding to that host -- the host you are doing the blacklisting on. Then use the remote IP that is reported in that line.

However, if the IP that you end up wanting to blacklist is one of your secondary MXes or otherwise an authorized host that may forward a lot of your mail on to you, then you are trying to blacklist on the wrong host. If you blacklist one of your secondary MXes, you're likely to block a lot of legitimate e-mail.

share|improve this answer
Thanks for your ans. but my question is little different, we are in email maketing. we send mail from remote smtp connection and every mail have information of both server (relay server and server from mail originate) in email header. my question if any isp black list my server then witch server is black listed relay server or server form mail originated. – John P Jan 2 '12 at 6:23
@Anmay - it can be any, depending on the actions of abuse-department of the owners of Source IP-netblock... and blacklist policy. Just don't generate shit!!! – Lazy Badger Jan 2 '12 at 14:56
It is almost certainly the relay server, not the originating one. Blacklisting the originating server has to be done once the e-mail has been received (because it requires analysis of the headers), so it's much more resource intensive than blacklisting based on the IP of the relay. – Sean Reifschneider Jan 6 '12 at 2:34

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.