I have an email list of addresses and need to incorporate them into a mailing list. How do I do this?

By default Thunderbird adds email addresses your enter info a new message to the Collected Address Book. If they are going into your Personal Address Book someone changed the default. Just to keep terminology correct, Thunderbird has Address Books and Mailing Lists You get 2 default address books when Thunderbird is installed. The Personal and the Collected books. You can create your own new address books but you cannot delete the 2 default books. You can create Mailing Lists inside any address book to send messages to groups that you use frequently. They are a subgroup of contacts that already exist in the address book where you create the mailing list. You cannot add members to a mailing list directly by typing addresses into an address field of a new message that you are creating. Here is the info on mailing lists. Not to be confused with an address book. http://kb.mozillazine.org/Thunderbird_:_FAQs_:_Create_Mailing_List