1. Adding a new identity for your Thunderbird email client will allow you to choose which return address people will see on emails they receive from you.
In this example, I set up a new identity which permits me to set my EE email address as my return address. Doing this lets me send mail from my CUIT mail account that appears as if it came from my EE mail account.
To begin adding a new identity in Thunderbird, go to the Edit menu and select account settings. When the "Account Settings" dialog box appears highlight your CUNIX mail account on the left hand side of the page and click the "Manage Identities" button.
2. When the "Identities for Account" dialog box appears click "Add ..."
3. In the "Id Settings" dialog box enter your full name and your EE email address in the Email Address field and click Ok.
4. Now, if everything was set correctly you should be able to choose between sending from your cunix and ee mail addresses by toggling between addresses in the drop down menu next to the From: field in all of your compositions.