Severe Email Delivery Issues

Posted September 4, 2014 5.1k views


So, we are experiencing horrid email delivery issues to Google, Hotmail & Yahoo.

Our MTA is Postfix, running on a Centos box with Virtualmin/Webmin running too. All emails are DKIM signed and we have valid PTR and SPF records also. I have tested our emails with various DKIM/SPF & SpamAssassin checking tools and the results are as follows (using Port25’s tool):

SPF check:          pass
DKIM check:         pass
Sender-ID check:    pass
SpamAssassin check: ham

I have also checked and it appears that Gmail can see that the emails are signed & SPF works etc.. I have checked to see if our IP appears on any blacklists and the results are all clean, but still we cannot get delivery to most email services. Errors received in the mail log as as per the following (email addresses removed for privacy):


to=<>,[]:25, delay=59400, delays=59400/0.06/0.06/0.01, dsn=4.7.1, status=deferred (host[] said: 421 4.7.1 [TS03] All messages from will be permanently deferred; Retrying will NOT succeed. See (in reply to MAIL FROM command))


to=<>,[]:25, delay=1.2, delays=0.08/0/0.49/0.67, dsn=2.0.0, status=sent (250  <> Queued mail for delivery)

None of the emails are delivered successfully. I have been in touch with both Yahoo and Hotmail via their respective forms and have signed up to Hotmail’s SNDS & JMRP and Yahoo’s JMRP. Neither of the JMRP’s have sent any reported emails through and SNDS says our IP is normal and that we’re not blocked.

Has anyone experienced similar before? I would massively appreciate ideas/thoughts/feedback



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4 answers

Even though their JMRPs are saying you’re not being blocked, that message from Yahoo certainly sounds like you may have an IP that was previously blacklisted. It’s often hard to do bulk mail from a cloud server when the IP has changed hands many times.

I know it’s not a great answer, but you might want to snapshot your server and try to recreate it with a different IP. While they’re an extra cost services like sendgrid and Mandrill are great for this sort of thing.

I have similar problems with Yahoo, AOL and T-Online. You might have an IP address that was formerly assigned to someone who had an open-relay due to mis-configuration or because he actively spammed himself. Unfortunately this can only be resolved by working with the provider’s postmasters. Unfortunately some of them don’t like to play ball with you. I have a very hard time with AOL. sigh.

If they say you are “unblocked”, I guess there is not much you can do. Maybe contact them again and tell them that you still get these messages, even after you got whitelisted and/or comply with all their rules.

Hi, i’ve same problem..
How can check if i’m blacklisted on yahoo?
What’s JMRPs? online checker?


Hi guys.

Thanks for your comments.

Okay so basically I persevered for as long as possible to try to build a good IP/sending reputation, but there was no success. I’m definitely inclined to believe due to the poor history of the IP address (or that block of up addresses) I would never be able to reach a decent level of deliverability.

All transactions emails are now being handled by Mandrill and deliverability is excellent. The pricing structure is great (free if you’re only small!). I believe Sendgrid offer a similar service, but from personal experience, Mandrill is fantastic.

blondie63 - JMRP is ‘Junk Mail Reporting Program’. It’s a system whereby when a user marks an email which they receive as spam, JMRP will send you a notification so that message quality can be improved (and you can remove that user from your email list!!)