I have DKIM, SPF and DMARC records and I’ve validated them with the Dmarcian online checkers. I’ve sent an email to my gmail account and the headers also show “Pass”. I’ve checked the spam blockers… but optonline dot net (and possibly me dot com) are rejecting my emails with some version of a 550 code eg:
Reason: 550 5.7.0 Your mail from 159.253.63.185 was rejected. We can’t currently accept your message.
Any suggestions on what to do about this as optonline dot net’s help desk is unresponsive.
You might try using one of the services that auto-reply to incoming messages with an analysis of any problems.
Here are the ones I use:
https://mxtoolbox.com/deliverability
Hopefully you’ll get some helpful feedback. Feel free to check back in here with the results.
(I’d like to see dmarcian add a similar tool.)
Many thanks
I tried the mail-test.com version and it gives 10/10
The mxtoolbox one didn’t respond
Anyway, it looks as if the headers are well formed, so why optonline rejects them remains a mystery.
Optonline doesn’t appear to support DMARC (check reporters here: https://us.dmarcian.com/dmarc-data-providers/), so it’s unlikely that the rejection you’re experiencing is due to a DMARC failure.
At the same time, it’s worthwhile to make sure that your messages are actually passing DMARC (simply verifying that you have a DMARC policy, that you have a DKIM key, that you have SPF in place, is not enough) by using a tool such as dmarcian’s RUA analysis service to see whether reported traffic is actually passing DMARC successfully.
If that all checks out, you might have to continue trying to get a response out of optonline.
