Send As - Distribution Group, Shared mailbox, or user alias address in Outlook 2011 for mac
This article will help you setup your Outlook 2011 for Mac to be able to send as an Alias, Distribution Group, or Shared Mailbox.
Please note: You must first set the "Send As" permissions on the server.
Now that the rest of the box opened up, we can fill out the rest of the form. For the Username, you want to put in your real email address. This is the one that will be used for authentication. Next, you want to make sure that IMAP is the Type you are using, for the incoming server, just put a . in the box. For the outgoing server, you want to use smtp.office365.com. You want to check the first box to override the Port, and make sure you change the port to 587. Then you want to check the box that says "Use SSL to connect"
Once you add the account, you will see some new fields we have to fill out to make this work. First, you might want to change your "Full Name". This will be the display name used when you send an email from the shared mailbox. You then want to verify that the "E-Mail address" is the correct email address of the Shared mailbox. Next, for the Username & Password fields, you want to use your real account for authentication. Next, click More Options
You can now go and create a new email. You should have a From drop down. You need to choose your new Shared Mailbox to be the From address. You should now be able to send as that shared mailbox.