I don't think it's a global change by Microsoft.
If you're correct that the error is a certificate issue, it is within the realm
of possibilities that a particular O365 customer (provided
*.eurprd08.prod.outlook.com is O365) has created a send connector for a domain
that you host (or not, if t
Hi,
I see increasing reports that sending from MS365 (and similar) fails
with messages like these:
Server at *.eurprd08.prod.outlook.com returned '550 5.4.318
Message expired, connection reset (SuspiciousRemoteServerError)(450
4.4.318 Connection was
closed abruptly (SuspiciousRemoteServerErr
