Automatic mailforward

[Martijn Eikelenboom]

We are experiencing an issue where I can't find a solution online.

Vendors send an email to a shared mailbox and these emails are forwarde to an external party for processing. Most emails are forwarde successfully, however, for two vendors the forwards are blocked.

We can't seem to figure out how to fix this.

Sender: our vendor

Recipient: our external processing party

[#2]

Forwarded messages break DMARC checks, and as a consequence are likely marked as spam/phish on recipient's side. This should not be a problem if the message is sent to another O365 tenant, unless there are another MTAs involved. In any case, check with the recipient's side, suggest some sort of a whitelisting if possible.