Do you have another email address that you would like to send from sometimes, but not always? Below are the steps to create a sending-only POP account in Outlook that will allow you to choose another email address when creating a new message.
Note: Do not send and receive with this account until you have shut off receiving in the Send/Receive settings as shown in Step 11. If you do, it is possible to duplicate your mailbox.
1. In Outlook, click File > Account Settings > Account Settings to bring up the Account Settings window.
2. Click the New...button to bring up the Add Account window then select Manual setup or additional serve types and click Next.
3. In the Add Account window, select POP or IMAP then click Next.
4. Enter your information as described below then click More Settings …
Your Name: This will display in the account drop-down menu in a new email message
Email Address: This should be your additional email address
Account Type: POP3
Incoming Mail Server: Outlook.Office365.com
Outgoing Mail Server: Smtp.Office365.com
User Name: This should be the email address you use to log into portal.microsoftonline.com
Password: This should be the password you use to log into portal.microsoftonline.com
5. In the Internet E-mail Settings window, click the Outgoing Server tab then check the box for My outgoing server (SMTP) requires authentication.
6. In the Internet-Email Settings window click the Advanced tab then enter the information as described below and click OK.
Incoming server (POP3) - 995
This server requires an encrypted connection (SSL) - should be checked
Outgoing server (SMTP) - 587
Use the following type of encrypted connection - TLS
Leave a copy of messages on the server - should be checked
7. In the Add Account window, click Next. You will then see a Test Account Settings window appear that should complete two tests successfully. If either of the tests fail, you need to go back through Steps 4-6 and verify all of the information you entered is correct.
8. Click Close in the Test Account Settings window then click Finish in the Add Account window.
9. Close any remaining windows so you are back on the main Outlook window then click the Send / Receive tab > Send/Receive Groups > Define Send/Receive Groups.
10. In the Send/Receive Groups window, highlight All Accounts Online and Offline then click Edit.
11. In the Send/Receive Settings - All Accounts window, select the account for the alternate email address you just added then uncheck Receive mail items and click OK.
12. Click Close on the Send/Receive Groups window then close and restart Outlook.
13. Congratulations! You can now send with an additional email address. Simply compose a new email then click the From drop-down to choose the email address you want to send from.
It is also important to note that when someone replies to an email sent from an additional email address it will appear in your normal inbox unless you create a mail rule that moves incoming messages to the additional email address to a specified folder. An example of such a rule is shown below.