Server Response: 550 5.7.3 Requested action aborted; user not authenticated
Right-click on the account name in the folder pane and select Properties.
- On the Servers tab
- Ensure that the Email username is your full email address
- Ensure that Log on using clear text authentication is selected
- Select My server requires authentication
- Click Apply and OK
Remove any unsent messages from the outbox (below the account folders in the folder pane), then compose a new test message with a unique subject and send it to yourself. Post any new error message in your reply.