Mails are getting delay at Edge Servers

Question

Hello,

After analyzing the mail header found that mails are getting delayed at the Edge server. Attached screenshot.

Also checking at the network end, there have been no delay.

Please help me to mitigate this issue.

Answer 1

Enable the protocol logs for the receive connector on the Edge Servers and see if they are seeing these messages.

If so, it should tell you why its not accepting them:

https://learn.microsoft.com/en-us/exchange/mail-flow/connectors/configure-protocol-logging?view=exchserver-2019

IF you do not see them in the SMTP protocol logs, then open a ticket with 365 support. IF you are a 365 customer already, you can also look at the mail flow insights in EAC online:

https://learn.microsoft.com/en-us/exchange/monitoring/mail-flow-insights/mail-flow-insights