How to send email from an alias

To save a few bucks, I added a second domain to my existing Office 365 account which gave me two email addresses under that account – and but it means that is an alias of and by default you can’t send email from an alias in Outlook. You can only receive email to an alias.

Fortunately my search skills turned up a solution from the good people at I’m sharing the information here because it wasn’t easy to find and sometimes having another source pointing at it is a good thing.

You’ll find that original post here: It offers up 3 solutions. The first of which I think is the best and it worked for me. Here’s what it looks like.

  1. In your account settings, choose to add a new account and select to configure it manually.
  2. Choose for a POP3 account and fill out the server details.
    For most Exchange servers, the settings are as follows (port and encryption settings can be configured by clicking More Options…-> tab Advanced);

Your Name:
Your display name

E-mail Address:
The alias address of your Exchange mailbox

Incoming mail server:
Name of the Exchange server
For Office 365 accounts use:

Outgoing mail server (SMTP):
Name of the Exchange server
For Office 365 accounts use:



Port number POP3:

POP3 Encryption (SSL):

Port number SMTP:
587 (or 25 in non-default configurations)

SMTP encryption:

My outgoing server (SMTP) requires authentication:

  1. When configuring your account, make sure you configure it to leave a copy of the messages on the server and not to remove it after x-days.
  2. Once configured, you must go into your Send/Receive settings and disable this account from receiving mail to prevent duplicate messages coming in.
  1. Additionally, you must set the POP3 account to deliver new messages to your Exchange mailbox instead of a pst-file. This might sound a bit superfluous, as we just disabled the receiving of mail for the POP3 account anyway, but by doing so, you can get rid of the pst-file that the adding of the POP3 account created and (more importantly) your sent messages will be stored in the Sent Items folder of your Exchange mailbox.
    1. In the Account Settings dialog, select your POP3 account.
    2. At the bottom of the dialog, click the “Change Folder” button.
    3. Select the Inbox folder of your Exchange mailbox.
      Here I chose to have mail for this account do directly into a subfolder instead so I could easily identify it – Amy
    4. After restarting Outlook, you can remove the pst-file via the Data Files tab in Account Settings.

After all this configuring, you can now create a new message and switch between your Exchange account (holding your main address) and the POP3 account (holding your alias address) via the Accounts button (Outlook 2003/2007) or the From button (Outlook 2010/2013/2016).


Originally posted in 2017 this popular post was migrated over from our previous blog

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