Greetings - I have an Exchange 2010 and a user reported that she sent out an email on 9/1/2016 and it was delayed for a few hours until receipting received it.
I am trying to see how I would troubleshoot.
I pulled a message tracking log, however not sure how to read it. I also pulled up Queue Viewer and I do see this below. Not sure how to read this and but I do see 421 Error: Too many messages...