You can set up Thunderbird to use multiple from or reply-to addresses. This is especially useful for shared mailboxes where you want the from address to be that of the shared mailbox and not your regular address.

1. 1. From Windows: Open the Account Settings menu from the Tools menu
   2. From Linux: Open the Account Settings menu from the Edit menu
2. On the Account Settings page, click the “Manage Identities…” button
3. On the Identities page, click the “Add…” button
4. On the Settings tab, enter the appropriate information such as name you want to appear on emails (Your Name field) and Email Address
5. Click OK
6. Click OK
7. Click OK

Now when you compose a new message, you should have the option to choose the new identity in the From drop-down menu.