Automatically Reply on email address

Question

I manage my own email domain using Microsoft Exchange Online. I've configured the Mail Flow on the server so that any text before the @ on an email (for a specific subdomain), automatically routes to my own mailbox. It also adds information to the header to indicate that it has been routed.

These email addresses do not actually exist in exchange, it's just configured to accept them and send them to my mailbox. If I reply to these emails, the reply comes from my actual email address.

I'd like to configure my exchange so that if I were to reply to these emails, they would get automatically re-marked as coming from the same email as the incoming address. Is this possible?

i.e. If I receive an email on [e-mail], I want the reply address to be [e-mail], rather than [e-mail]

Answer 1

As far as I know, there is no such a mail flow rule to realize this. As a workaround, you could create that mailbox in Exchange. Assign your mailbox “Send As” permission to this account. Just like they mentioned in this thread.

When sending from Outlook client, just click “From” > “Other Email Address”. The record will remain there. Next time, you can easily choose that address in “From” drop-down menu.

Another option is described in this blog: How to add an alias to an Office 365 account and how to set up Outlook to send email messages as this alias