The Reply-all Storm Protection feature in Exchange Online helps protect your organization from unwanted and disruptive reply-all storms. Last year we updated the feature to give admins the ability to...
Updated Apr 23, 2022
Version 2.0
Blog Post
This is a bit off-topic but was there an unnotified change made in the way the "Exchange Online Forwarding" from a mailbox is working? Since last Friday, we see a change in how Exchange Online is forwarding mails.
I will use the example of a sender "x.y@gmail.com" to a recipient "x.y@exodomain.com" with a forwarding configured to "x.y@externaldomain.com"
Before Friday the "From (Envelope)" header of the forwarded mail was an automatically generated one from Exchange Online with an internal email domain.
In our example, this would be x.y+srs=metml=u4=externaldomain.com=x.y@exodomain.com
After Friday the "From (Envelope)" header is the mail address from the sender. The forwarding, therefore, is now getting rejected in many mail systems as the SPF is wrong.
In our example, this would be x.y@gmail.com
Can you please confirm that a change was made there and if this is the new expected behavior? A support ticket for that has been opened on Friday but we got no answer to that yet.