Change your email alias in Thunderbird
Your email address is: firstname.lastname@example.org e.g. email@example.com
You also have a more friendly email address (or email alias) based on your name. E.g.
When you log in to Thunderbird, you might find that messages from your account get sent as being from 'firstname.lastname@example.org'. You can change this so that your 'friendly' email alias is displayed instead.
To do this:
1. Click on Tools (in the menu bar) and Account Settings
2. In the right hand window pane, type your 'friendly' email address in the Email Address field:
3. Click OK to save your changes.