Deploy MTA Strict Transport Security
Thank you for your input! We will consider this functionality in upcoming releases if it will be popular.
Everyone, please continue voting for this feature if you consider it important.
Having so many issues with outgoing email to what we believe is Cisco filtered email domains that we need to be able to keep up with the times.
It's just really important to implant it !
Please do it !
man in the middle should be a thing of the past. please implement this feature. 2018 is a VERY long time ago for a feature request that is now more important then before.
Please implement this!
Update (26 Sep 2018): MTA-STS has been officially published as RFC 8461.