When I import an address book, I find that I can't simply choose the address book and have thunderbird send the email to the entire address book.... why?
On my base computer, I've been building my address books. On my base computer, when I start typing in the to: box the names of the address books come up and I'm able to select the address book, after which it appears in the To: for the message, and then when I hit send, all of the contacts in the address book get the message. So, I've been exporting the address books in csv format and saving them in my dropbox so that I can import them for use on my other computers and laptops. The interesting thing is that on the other computers, when I start typing in the To: box, the names of the imported address books don't come up. I can see the contacts pane, and I can look at the imported address books, but to send messages to the people in the address books, I have to actually select all that are then inserted into separate to: boxes..... which is very tedious and not as satisfactory in terms of managing groups through the use of address books. I must be doing something wrong.
Opaite Mbohovái (3)
What Thunderbird calls an 'address book' is actually a database of people and/or organisations. You can store their names, phone numbers, physical (postal) addresses and other information; you can include their email address too, but you don't have to. I think what you are referring to in your question is a list of email addresses, and that's what Thunderbird calls a 'contact list'. It is simply a list of email addresses to which you give a handy name -- 'family' or 'club members' for example. You can address an email to such a list and Thunderbird will send individual messages to all the addresses in it. I'm a bit confused as to how you have set up your computers because you've referred to 'address books' when I think you mean 'contact lists'. Anyway, if you want to send a single email to all the members of a group, a contact list is what you need.
I think that is what is happening, is that I'm exporting each contact list separately, thinking that is the way to keep them intact for importing. Then, when I import, I import each list separately, so then each list comes in as an imported address book. When that happens, Thunderbird sees a group of address books, rather than a group of contact lists, so I can't simply address to the individual address books, but rather have to select individual emails from the address books. I guess that what I have to do when I export, is to export the higher level address book that contains the multiple contacts list. I think I got into doing it the way I've been doing it after reading about exporting addresses for import into Gmail... by keeping the contacts lists separate, it keeps the lists intact as Gmail contacts groups so I don't have to go through the work of recreating the contacts groups in Gmail.
Do your other computers also use Thunderbird? If so, try Tools|Export and export each address book (e.g. Personal Address Book, Collected Addresses) to its own LDIF file. This will preserve your Mailing Lists. CSV files are not sufficiently sophisticated to be able to store nested structures such as Mailing Lists inside address book data files.