This posting demonstrates how to associate a "preferred email" address so alerts are sent to the preferred email address instead of the email associated with the logged in Microsoft ID. This sounds like a great feature but beware the following: the preferred email address is associated with the Microsoft ID. This means that every Visual Studio Online instance will send alerts to the specified preferred email. The preferred email address is not Visual Studio Online instance-specific.
To set the alternate email for all instances of Visual Studio accessed by the Microsoft ID, log in to the Visual Studio instance:
Click on the logged in username which shows a menu including menu items My profile and Sign out:
Notice below in the User Profile dialog, the preferred email address can be specified:
Once the preferred email address has been modified, click on the Save changes button in order to commit the changes.
After the preferred email address has been changed, an email will be sent to the preferred email address. A user must click on the email's conformation link thus verifying the preferred email and giving Visual Studio the green light to send alert related emails to the preferred email address.