Exim Mailman and Retry Rates

Operating System & Version
CentOS
cPanel & WHM Version
106

Coley1

Registered
Nov 9, 2022
1
0
1
U.S.
cPanel Access Level
Root Administrator
Greetings,



I am running a server that has cPanel/WHM with Exim and Mailman running fine except for the dreaded Yahoo issue that many others have had. This server is well secured and we follow best practices. The mailman lists are for a school that is fairly busy and sends around 5k emails per month. We have DMARC, SPF and DKIM on these domains as well. I have adjusted retry rules until I am blue in the face.



The error I am getting is this:



SMTP error from remote mail server after pipelined MAIL FROM:<[email protected]> SIZE=9550: 421 4.7.0 [TSS04] Messages from x.x.x.x temporarily deferred due to unexpected volume or user complaints - 4.16.55.1; see https://postmaster.yahooinc.com/error-codes



Would anyone out there be willing to share what they set on the following?



Tweak Settings Retry:

Exim Retry Rules and throttling:

Mm_cfg.py settings for mailman:



Any other suggestions as well.



Thanks!
 

cPRex

Jurassic Moderator
Staff member
Oct 19, 2014
13,463
2,114
363
cPanel Access Level
Root Administrator
Hey there! That doesn't seem like an issue with the Exim settings, but a problem with Yahoo ratelimiting your specific server. I don't believe there will be anything you can do on the server-side to resolve that, so speaking with Yahoo is likely the best plan.

It does look like you're using a mailing list though - how are you handling bounces on that list?

I also use the ATT/Yahoo network for my personal mail, and I'm not aware of a "dreaded Yahoo" issue.