How to remove addresses from Thunderbird's autocomplete drop-down?

Question

When Thunderbird suggests email addresses for me as I type, there are many addresses there that I know are obsolete. How can I permanently remove them so they are never suggested to me again?

Answer 1

In Thunderbird 3, open the Address Book. There's a section called "Collected Addresses". Delete entries from there. Also (this is what tripped me up), make sure you don't have an explicit entry for the obsolete email address in "Personal Address Book".

Answer 2

You can find your answer here

Hope this wil help!

This one is about as counter-intuitive as it gets. The trick is that you don't delete auto-complete entries from the main Thunderbird window -- you delete them from the autocomplete cache as accessible from within a new email. * Turn auto-completion on * Open a new email * Within the email window, click the Contacts button (should create a pane at the left with the list of addresses) * Delete the entry you don't want.

I've done this successfully on my machine.