Good news on the adoption of SMTP TLS reporting: since the 25th of August 2020, we are seeing SMTP TLS reports being sent by Microsoft!
After Google, Comcast, and SocketLabs, Microsoft is now the fourth major email service that is sending RFC8460 SMTP TLS reports.
The support for SMTP TLS reporting from Microsoft did come as a bit of a surprise to us, as Microsoft is the only major email provider that is not yet sending DMARC reports. Nonetheless, would we like to thank Microsoft for embracing this standard, and massive congratulations to the developers at Microsoft who made this possible!
We are excited to see the adoption of SMTP TLS reporting growing steadily, as TLS related email issues are hard to monitor. SMTP TLS reporting also paves the way for broad adoption of MTA-STS.