Microsoft mail blocking (solved)

This affects all users with email addresses from a Microsoft email service (outlook.com, live.com, hotmail.com, etc.): Microsoft added the entire IP network where the OVMS server is located to their internal mail blocklist yesterday evening at 9:00 PM CET.

The server is officially registered with Microsoft as a dedicated server, so Microsoft is not adhering to its own rules here.

Unblocking has been requested; how long this will take is unknown.

Update 16:51 CET: the blocklist entry has been removed by Microsoft, mails to Microsoft domains get delivered again.