Delayed message issue from Outlook

Question

Exchange online one user have delayed message issue.

He sent one mail at 15:00 yesterday.

And all receivers received the delayed message at 3:40 this morning.

EAC message tracking shows this was delivered at 3:40.

Message time stamp in sender outlook shows 15:00 yesterday.

The message item was moved in his sent items automatically.

User said that sent messages including other messages are delayed.

I think it's coming from sender outlook, but there's no any NDR.

Would you please tell me the cause of root and how to investigate...?

Answer 1

Hi @Wonderwhy

Does this issue occur on internal users or external recipients or both? Is there any difference if the user send the same email from OWA rather than Outlook?
Do all the emails sent from that user have this delayed issue?

I would suggest you check the message header for this delayed email, copy the message header of the email into the following link, and check where the delay happened:
https://mha.azurewebsites.net/

Here is an article about this: https://practical365.com/how-to-read-email-message-headers/
Please Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.

---

If an Answer is helpful, please click "Accept Answer" and upvote it.

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.