Hello guys,

This is an issue that is currently ongoing and hard to realize without having the bigger picture.

Earlier today, 15:00 / 3:00 PM German / European Time, there started to be world wide issues linked to sending and receiving e-mails for multiple people. Those issues are linked to the Microsoft Exchange servers and the services of Microsoft. First this it not a hate post against Microsoft or America but a post to just give every Sys Admin a heads up so you know where the issue is and that it's not on your end. Parts are my speculation as to why but the issue remains present.

The issue is the following. When some people send a mail, it is moved to the send items folder but is not delivered. No matter if the mail was send from you to you or to people inside or outside your company. HOWEVER you will still receive mails from those who are not yet affected.

This means if Mark from HR sends a mail to Susan in Accounting, Susan does not receive the mail. But when Susan sends a mail to Mark, Mark receives the mail as usual. If Mark sends a mail to himself for testing it still looks like it's send correctly since it left the outbox and appears in the send items folder.

It does not matter if the mails you receive are from inside your domain or from outside. There will be users who are affected while others aren't. BUT don't worry. The send mails are not lost. They are simply queue on one of the microsoft mail servers that take care of sending the mails while the servers or services responsible for delivering the mails are not affected.

See it as a delay in mail delivery. If someone asks explain it as the mails you send are deliverd by Driver A who got stuck in a traffic jam while the mail someone send to you was delivered by Driver B who didn't get stuck in a traffic jam. Should give none IT people a simple real life example of the issue.

Those delays can range from anywhere of 10 minutes to 2 hrs. At least as far as I have seen. The users likely won't notice unless they send time sensitive mails where someone is waiting for the mail. Like they are on the phone and tell each other that the mail was send. Otherwise you won't even know if your mails are delayed or not.

Now to my speculation part. I assume that Microsoft is pushing an update to their 365 Exchange servers in waves and not everyone from the same domain is hosted on the same server. So some users are on Server A and others on Server B or C. Now that the updates are roled out the service gets a hiccup and struggles to work of the queue for some reason and may affect some users more than others.

Just be aware that this is an issue where you don't have any control over unless of course you work at Microsoft and deployed a bad update to your servers.

Stay positive guys and keep doing the great work you have been doing so far.