Emails getting blocked/denied... sometimes

[acepek]

Thanks for this software. It rocks.

I am getting some mail bounced back. I’ve got all green/ok on the Status page.

DNSEC is configured correctly
dkim=pass
spf=pass
This is all good: http://mxtoolbox.com/domain/box.paloaltoimpactcenter.com/
Not on any blacklists I could find

It’s happened with two different recipients with the following error codes…

1): Subject: Undelivered Mail Returned to Sender
Action: failed
Status: 5.0.0
Diagnostic-Code: smtp; 554 Denied [CS]
[35ccc275.0.14161064.00-2147.27390049.p02c11m062.mxlogic.net] (Mode:
normal)

2): Subject: Undelivered Mail Returned to Sender
Action: failed
Status: 5.3.0
Diagnostic-Code: smtp; 553 5.3.0 nlpi185 DNSBL:RBL 521< 104.130.132.74
_is_blocked.__For_information_see_http://att.net/blocks

Any ideas what to try next? Everything seems good on my end.

Thanks!

[v60fan]

For 1), it’s an issue with the content of the email I believe.
http://www.mailchannels.com/2013/10/mxlogic-554-denied-cs/
I had this once and followed the instructions to manually remove my box’s IP. The key step for me was: 3. Send a copy of the message with the original headers to SaaS_falsepositives@mcafeesubmissions.com

For 2), it’s going to be something similar but with AT&T.

Usually for these you have to contact the operator of the system you’re trying to email to/through to get the reputation of your box improved/known/removed from any bad or block list.