How to diagnose issues with receiving emails?

[martin MHC]

Hello!
I have a server with WHM 74.0.10 which seems to be having issues sending *some* emails and receiving *some* emails.

No email (exim, tweaks, etc.) settings have been changed on the server, as far as I am aware.

My query is relating to how to DIAGNOSE not receiving certain emails.

I have searched the exim logs ( /var/log/exim_mainlog ; var/log/exim_reject_log ) and the main maillog ( /var/log/maillog ) and seen nothing that stands out (but I am NOT the most experienced with exim detection issues):

I have not received expected automatic emails (from my Anti-virus provider @eset.co.uk), and clients are reporting this INCONSISTENTLY across the server.
So my query is this:

Using WHM how can I effectively search out and diagnose reasons emails do not reach exim, before possibly having to raise a ticket? Some common things to do such as search the exim logs or suchlike to check if I can find why certain emails do not appear in the mailbox.



Many thanks


p.s> server domains all fully pass testing tools such as mxtoolbox etc

 

[cPanelMichael]

Hello @martin MHC,

The following resource is a good place to start:

Tutorial - Why didn't my email get delivered? or where did my email go?

Can you review this guide and let us know if it helps?

Thank you.

 

[martin MHC]

@cPanelMichael THanks for this. I have edited and clarified my question as to specifically how to approach non-received emails. Thank you.

 

[cPanelMichael]

Hello @martin MHC,

If you're not seeing anything in /var/log/exim_rejectlog or /var/log/exim_mainlog at the times when this happens, then it's generally an issue on the server where the emails are sent from. We're happy to take a closer look via a support ticket if you'd like us to verify if there's anything in the Exim logs to suggest to cause of the problem.

Thank you.

 

[martin MHC]

Hi @cPanelMichael - I had raised aticket, and found that SOME of the missing expected emails (cpanel ones) was due to the Exim report that "Could not complete sender verify callout" was in the /var/log/exim_mainlog (I had not noted this as the issue was marked as "temporarily reject" ).

Other expected emails did not appear in the logs (mainlog or rejectlog) but chasing up the respective companies some of their emails have come through, so it's abiguous if the cause is this end or their end.

I will update here with further information when it occurs.

Cheers