Exam 70-345 topic 1 question 103 discussion

You work for a company named Litware, Inc. that hosts all email in Exchange Online.
A user named User1 sends an email message to an external user. User1 discovers that the email message is delayed for two hours before being delivered.
The external user sends you the message header of the delayed message.
You need to identify which host in the message path is responsible for the delivery delay.
What should you do?