Hi @Rising Flight ,
No, for Exchange, the two addresses are both considered as a mailbox.
Neither transport rules nor inbox rules could be applied to the secondary address.
And the message tracking log will not recognize it as a recipient.
For more details: https://learn.microsoft.com/en-us/exchange/recipients/user-mailboxes/email-addresses?view=exchserver-2019
The additional addresses are called proxy addresses. A proxy address lets a user receive email that's sent to a different email address. Any email message sent to the user's proxy address is delivered to their primary email address, which is also known as the primary SMTP address or the default reply address.
Best regards,
Lou
If the response is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.