Different NDRs from 365

Copper Contributor

I have a tenant with 365. When I sent an email to an invalid recipient, 365 responds with:


Remote Server returned '554 5.4.1 < #5.4.1 smtp; 550 5.4.1 Recipient address rejected: Access denied. AS(20xx0xxx) []>'


However, with another tenant on 365, when I send an email to an invalid recipient, I get a really handy NDR with great information for the end user saying "The recipient isn't found". In fact, they get a different error code 550.5.1.1.


My question is, why doesn't my 365 send out those helpful kinds of NDRs for people who send emails to invalid addresses in 365?

4 Replies
Thanks Andres. That sounds like exactly what it is. Any idea why I receive enhanced NDR from some 365 customers and not from others?
Probably because, a different component rejecting the message depending on DBEB enabled or not

@Andres Gorzelany Thank you for your assistance.

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