Microsoft Mail unreachable

[DuckRed]

I host mail for a large number of users.
Since around 5am today (11 October 2023) we have noticed mail going to some exchange ( onmicrosoft ) hosted domains does not get delivered.
Many other domains are accepting our mail fine - even exchange ( onmicrosoft ) mail servers are accepting our mail.

 

[Web Telecom Services]

I host mail for a large number of users.
Since around 5am today (11 October 2023) we have noticed mail going to some exchange ( onmicrosoft ) hosted domains does not get delivered.
Many other domains are accepting our mail fine - even exchange ( onmicrosoft ) mail servers are accepting our mail.

We see the same thing with certain domains on Microsoft, server response is 451 4.7.500 Server busy

 

[Jade @ Absolute Hosting]

Had similar on one server and had to swap mta IP, that seemed to help

 

[Jade @ Absolute Hosting]

Hmmm just been informed now that the fix was temporary.

We do have a ticket open with MS and will advise that it’s multiple hosts affected

 

[Jade @ Absolute Hosting]

MS have confirmed to @Web Telecom Services and ourselves that they are aware of the issue and attending.

 

[DuckRed]

Thanks for your responses.
We have heard that some servers are / were having DDOS attacks, hence the throttling by Microsoft