Sending email as alias in office365?

Assuming the following:

You have a user with mailbox and e-mail address userA@contoso.com and you want him to receive and send mail from an address userA@aliasdomain.com.

Do the following:

1. Create a distribution group with e-mail address, the alias f.e. userA@aliasdomain.com

2. Add the user's primary account as a member to this distribution group (Members => userA@contoso.com) to make sure e-mail gets delivered to his mailbox.

3. Set External Senders as required

4. Make sure membership approval is set to not allow other members

5. Set Send As permissions for userA@contoso.com

Now this user can receive e-mail on his new userA@aliasdomain.com e-mail address + send from this e-mail. The only thing he needs to do is in Outlook or OWA select the From and change it to the alias address.

Cheers,

Joey