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anarion 19th March 2007 16:00

Postfix and sending with multiple domains
I'm having trouble finding the correct documentation for some problems that one of our servers is having with sending mail. We host multiple clients using virtual hosts and we use postfix as a MTA to send web form information both to their users and to the client. Some larger email providers are blocking these emails because they think that it is spam. Some of the blocks may be blocking other people in the rest of the block of IPs (eg, 55.55.55.n) that we do not control. I think this is primarily because these email providers do not like emails from one domain being sent from another hostname.

Anyway, I am just looking for documentation/forum threads, etc. on how to send up sending services for multiple domains. I do not need to setup accounts on the server because this is not marked as the mail server in DNS (I can setup these accounts if it is necessary, but I'm looking to avoid these issues).

Any help would be greatly appreciated. Thanks in advance!

till 20th March 2007 11:19

Email servers in multo domain setups are always sending mails from there primary domain, so that nothing unusual and most likely not the thing which is causing your mails to be blacklisted.

Have you checked that your server is not a open relay and that your IP's are not blacklisted?

anarion 20th March 2007 15:54

I've run the open relay test and it comes back negative (actually the test fails, I think because of firewall settings). Some of our IPs have been blacklisted, but it is difficult to tell which IP is blocked. We 'own' the first fifty or so IPs in our subnet and, for example, roadrunner has from time to time blocked the whole subnet.

Just for clarification... it's not considering fishy if an email for comes from

Many times were able to find out we're blocked, but it is just a pain to hunt down two of these every month (or whatever the frequency is).

Thanks for you input.

falko 20th March 2007 17:01

Please check if you're blacklisted:

anarion 20th March 2007 17:19

Thanks for the link! The status is OK on all of the lists (except one which timed out). What triggered this was a message like this:


Reporting-MTA: dns;
X-Postfix-Queue-ID: 7F090E2743
X-Postfix-Sender: rfc822;
Arrival-Date: Sun, 18 Mar 2007 22:01:05 -0500 (CDT)

Final-Recipient: rfc822;
Action: failed
Status: 5.0.0
Diagnostic-Code: X-Postfix; host[] said: 550 550
    Dynamic/zombied/spam IPs blocked. Write (in reply to MAIL FROM command)

Any thoughts? This is actually the first email/log message that I've seen from Earthlink and so I was just worried about problems further down the line.

Thanks again!

falko 21st March 2007 16:13

Is your mail server on a dynamic IP address? It's possible that Earthlink uses a special blacklist for dynamic IP addresses that aren't listed on the other blacklists.

anarion 21st March 2007 16:17

The server uses a static IP. I was thinking that this might be a pretty generic message used by their spam blocking services. Not very helpful to say the least.

falko 22nd March 2007 18:52

Maybe it's the best to contact the Earthlink support and ask why your emails are blocked.

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