Mails not been delivered

[Pravin Bundhoo]

Dear Team,

Please note that we are having recurrnet issues on mails as mails are not being delivered. The mails are frequently being stuck as the delivery status.

Can you please assist on same urgently?

Regards,

Pravin Bundhoo 

[Ken Stieers]

What do the mail logs tell you?  What does tracking tell you for mail to the domains?  There might be enough info there. 

If you have to get deeper you can try Domain Debug logs. You can pick one of the domains, enable a Domain Debug log, and see what's going on when you hit the Retry Delivery button.

In System Administration/Log Subscriptions, click Add new log subscription, pick Domain Debug Log, give it a log name, enter the domain, set the number of SMTP sessions to 2 or 3... Submit/commit.   Then go to Monitor/Delivery Status, find the domain you're testing and hit Retry delivery a couple of times. 

Then look at the debug logs... 

You might have to repeat this for multiple domains to see if they have different issues.

[Dustin Anderson]

Without a lot of info, I can make a couple guesses at the possible issue. As Ken stated you can do the debug. I'm also assuming this is on outgoing emails.

My gut tells me it's probably a DNS issue. There are some ways to test, but what I do it pull up a command prompt, enter nslookup, do set type=mx and look up the domain in question. then I take the mx and try to ping from the esa. If you get nothing, you know it can't lookup the server. if it can you ruled that out.

Another could be TLS, do you require encryption? are you limited to only TLS 1.2? Logs will show this error as it can't set up a session.