If you have a website and is setting up an email account with Outlook to avoid using Horde, Roundcube or SquirrelMail in your browser, you will likely receive the Microsoft Outlook Test Message a few seconds after setting up for each added account. The sender will show as Microsoft Outlook on your desktop client and Note to Self on your mobile device client.
This is an e-mail message sent automatically by Microsoft Outlook while testing the settings for your account.
It is mandatory the first time but on updates to the settings, you can deselect the box to automatically test. To make sure your settings are always correct, I recommend leaving it selected so that you will know if your settings are correct if you made changes.
Benefits of Test Message
If you are not currently setting up Outlook to retrieve or send your mail and see it in your inbox or worse, in the trash folder, it is an indication that someone has gotten access to your credentials and you should get your email password changed immediately. Change it from a computer that you are sure not to have any ransomware, keyboard capturing and spyware.
Some mobile users (ie. Windows Phone) may see the Microsoft Outlook Test Message while using their devices. To confirm if it is a bug, please log into your webmail client using one of your free Internet browsers to see if it is there or if it is missing. If the message is not there, you have just confirmed that it is a bug and should check to see if an update with a fix has been released for your device.
To see if the test originated from your system, please check the headers of the email. The Graphical User Interface (GUI) in Outlook will differ from each version but access is about the same. To make things simple for yourself, use Horde, Roundcube, SquirrelMail or Outlook Web Access.
The Microsoft Outlook Test Message feature has been available since Outlook 2002.