When creating a new (shared)mailbox to Office 365 with a primary email address, you have the option to add multiple alias email addresses too.
When sending an email to one of these alias addresses, the recepient will always see the primary email address as the address the mail was sent to in his email client (for example Outlook).
If you want to see to which alias the email was actually sent, you have to look into the email header.
So the question is: is there a way to show the alias instead of the primary email address for incoming mails in the email client?
Best Answer
Find the following similar cases for your reference:
Exchange 2010 - Retaining the 'alias' in the 'To:' field after the message is delivered (for rules, routing, etc.)
emails sent internally to alias address doesn't have proper To: address