Scenario: It was reported that mailboxes were receiving message delays when receiving a message. The customer stated the time was 15-20 minutes before the message would make it into the mailbox. The message header was showing the delay, but not showing what was causing the delay.
Cause: We found that one of the servers was not accepting any messages, thus causing that hop to be delayed. 15 minutes was how long it would take for the next hop to occur again. When the next hop would happen it would select a different server to send the message.
Troubleshooting: We ran the following command to see where the message was being delayed.
get-transportserver | Get-messagetrackinglog -eventID Defer -Start 3/18/15 | Export-csv C:defer.csv
When we opened the csv file we found the common Servername that was having the issue. When we logged onto the server to attempt to restart some Exchange services, it was apparent the server was having other issues. We rebooted the server and all was well when it came online again.
Ex-Shell 