Update 11/13/2023: We added new information on how to know when this change is released to your organization.
Today, we are announcing an update to our requirements for SMTP relay through Exchange ...
Updated Feb 22, 2024
Version 19.0
Blog Post
Carolyn_Liu
Microsoft
Microsoft"In this case:
- SMTP certificate domain on the SMTP connection; or
- SMTP envelope sender domain in the MAIL FROM command (P1 sender domain).
1 a) cannot be satisfied in our scenaroio So we are relying on 1 b).
When email reached us, we issue the same "mail from" command as what is in the original "mail from" command(from exchange).
In some cases, mails reaching our server come with an empty return path, ie., "mail from" from exchange has an empty value. Hence the "mail from" command issued by us is also having an empty value.
In this cases will the mail delivery be impacted?"
Answer: yes, it will be. That's what is listed in the blog. You have to use cert (which has the domain as accepteddomain) to authenticate the mails. Otherwise they will be rejected once the change is deployed.