451 Temporarily unable to process your email. Please try again later.

Legin76

Well-Known Member
Dec 11, 2007
178
4
68
Hi

One of my servers appears to be bouncing some incoming emails with the error "451 Temporarily unable to process your email. Please try again later. (in reply to RCPT command)".

It appears to be a bit random.. Some emails from the same sender will be received but others will bounce.

I'm sure I've seen a setting that does something similar to this but can't find it now.

CENTOS 6.7 x86_64 xenpv – WHM 11.52.1 (build 0)
 
Last edited:

cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,884
2,245
463
Hello :)

You can review /var/log/exim_mainlog to determine the exact reason for the failure. EX:

Code:
exigrep [email protected] /var/log/exim_mainlog
Thank you.
 

Legin76

Well-Known Member
Dec 11, 2007
178
4
68
It appears to be something to do with the grey listing...

2015-11-11 10:51:18 H=ftx-008-i765.relay.changedname.net [01.12.345.67]:7912 X=TLSv1.2:DHE-RSA-AES256-GCM-SHA384:256 CV=no F=<[email protected]> temporarily rejected RCPT <[email protected]>: Deferred due to greylisting. Host: '01.12.345.67' From: '[email protected]' To: '[email protected]' SPF: 'unchecked'

2015-11-11 11:00:28 H=ftx-008-i771.relay.changedname.net [01.12.345.67]:14402 X=TLSv1.2:DHE-RSA-AES256-GCM-SHA384:256 CV=no F=<[email protected]> temporarily rejected RCPT <[email protected]>: Deferred due to greylisting. Host: '01.12.345.67' From: '[email protected]' To: '[email protected]' SPF: 'unchecked'
 

Legin76

Well-Known Member
Dec 11, 2007
178
4
68
The Greylisting settings are as follows..


Deferral Period (in minutes)
10

Resend Acceptance Period (in minutes)
240

Record Expiration Time (in minutes)
4320

Bypass Greylisting for Hosts with Valid SPF Records
Un-checked
 

Legin76

Well-Known Member
Dec 11, 2007
178
4
68
I've reduced it to 5 minutes although it appears that the IP is different for each send attempt.

I thought the greylist bounce message was one that went to the server so it would retry and not to the sender.

Would turning on "Bypass Greylisting for Hosts with Valid SPF Records" help?
 

cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,884
2,245
463
Yes, you can enable that option if you want to allow email from hosts with valid SPF records to skip the greylisting functionality.

Thank you.