Have searched Forums for quite some time now. Cannot find a correct answer to: how do I prevent my old email address from appearing as the "from:" address

Question

Have searched Forums for quite some time now. Cannot find a correct answer to: how do I prevent my old email address from appearing as the "from:" address when I use a "send this" link on a webpage/news article. The email window opens and automatically inserts my old Hotmail address instead of the Yahoo address I've used for a long time. (The drop-down won't let me change it or delete it.) Thanks.

Answer 1

Do you get a drop down list with suggestions if you clear that "from" field and click elsewhere on that page to move the focus off that field and then double-click again in that field or start typing the first letters of that unwanted email address?
Use these steps to remove saved (form) data from a drop down list:
#Click the (empty) input field on the web page to open the drop down list
#Highlight an entry in the drop down list
#Press the Delete key (on Mac: Shift+Delete) to remove it.
*Form History Control: https://addons.mozilla.org/firefox/addon/form-history-control/
*Tahoe Data Manager: https://addons.mozilla.org/firefox/addon/data-manager/