Delivery issues and mail delays

[spacemeb]

Hello, 

Outgoing and/ or incoming mail flow has/have huge delays, mails are not delivered to specific domains and multiple smtp error messages are observed.

Unfortunately, it happened to our appliances 3 times in 2021 for different reasons each time, so i decided to discuss that with the community here. 

I believe that every engineer/administrator that respects himself needs to be able to basic troublesboot the issue before a tac case.

I usually check the status, capacity, message tracking, overview and of course the displaalerts.

Tophosts and status commands are helpful for sure. 

Also telnet tests to your smtp server to check connectivity.

Apart from the above, are you aware of any other spots to check or commands that would be handful? 

I know that such issues can be triggered by various reasons, thus we cannot isolate the problem.. but a guide related to what we should do under these circumstances would be extemely useful.

Looking forward to hearing from you,

Kind regards,

Meb

[Udupi Krishna.]

I feel the plan you have gathered is pretty good to begin with. While a few more can be added, you could consider workqueue verification as part of the troubleshooting plan.

Workqueue status and workqueue rate can provide information if there are emails stuck due to various reasons which can sometimes create email delays. While troubleshooting workqueue issues may be limited due to lack of visibility to all the logs, but you can still run diagnostic, verify each engine status, restart them (if deemed necessary) etc.

Mail logs, hoststatus, smtp routes are few other things i would look at for troubleshooting similar issues.