Error sending emails from Service Manager

[7oaks]

Has anyone had emails similar to these in the last hour? or could someone point me in the right direction if they've seen this before.

The following message to <xxxxx@xxxxx> was undeliverable.
The reason for the problem:
5.1.0 - Unknown address error 550-'5.4.1 Recipient address rejected: Access denied. AS(201806281) Invalid Date'

[Alisha]

Yes, we've had lots of undeliverable messages too.

 

This is the mail system at host live.hornbill.com.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can
delete your own text from the attached returned message.
 

[Steve Giller]

We have also seen some issues delivering to Customers with Exchange Online mailboxes, these seem to have cleared up now - are you still seeing issues or are things back to normal?

[Alisha]

All resolved, thanks Steve.

[7oaks]

Tested successfully this morning too thanks.