Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

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

Got a minor problem and don't know where to begin looking. I've checked DNSBL lists for the IP of the server and it's free, not on any lists anywhere.

For some reason emails from my domain are not getting through to a list of about 200 people when we send out emails. I don't get ANY bounce backs at all! The list is about 700 people in total. We send out about once a week to this list, most of them are getting the email, but around 200 of them are not.

At this point since we don't get any bounce backs at all and the IP is not blocked I don't know where to go with it. Are there a lot of internal lists and anyway to check those?

We are talking scattered emails like Yahoo and Juno nothing set to one main server. Then there are a bunch of individual domains.

share|improve this question
Are you using multiple SMTP relays to send the message out or do they all come from the same sending server? – EasyEcho Nov 2 '12 at 14:26
PHP Script same server. – jfreak53 Nov 2 '12 at 14:35
Are you sure that you have checked both the multi-RBL (, Cisco Ironport ( and other vendor-specific blacklists (like Barracuda) on all your SMTP relays? – pauska Nov 2 '12 at 14:36

Going from "some recipients don't recieve our email" to "our domain is being blocked" is a leap if you ask me. Start with the basics:

Find one recipient that didn't recieve your email. Check that email address, is it valid (was the email address misspelled per chance)? Use an external service to test the email address. Check the MX records for that recipient, are they valid? Attempt to establish a telnet connection to port 25 on those MX records, does that work? Attempt to send an email to the recipient via telnet, does that work? Enable logging on your SMTP server and look at those logs, do they give you any clues?

share|improve this answer

Check your smtp and MTA logs or if on exchange use message tracking to see what happened to the message for those specific domain / users

As a test pick 5 or 6 addresses of those who aren't receiving your message and then send them a test to ensure they got it.

share|improve this answer

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.