I think the addresses need to exist in your address book before you can add them to the mailing list. The easiest way to do this is to add the addresses in the address book and then drag them to the mailing list...

The addresses are in an address book. I cannot then add them to a new list. I can add them to an existing list but that does not help.

The addresses should be in the same address book as the mailing list. Then you can add them, also to a new list. When you create the list and begin typing the address, the auto completion shows the addresses from that address book and you can pick the ones you want to add...

That I understand. Here is a bit more information

I have several address books. Let's say A, B and C. In "C" I have a number of addresses. I then create a new list under "C". I can type in the addresses I want in "C-list". That sort of works. Sometimes they don't show after closing then re opening the "C-list". Alternatively, one is supposed to be able to select multiple addresses from "C" then drag and drop them in to "C-list". That does not work.

In "A" it works in lists that pre-existed but not in a new list. This used to work prior to version 24.x. I have now upgraded to 31.3 and it still does not work as advertised. I thought of placing the addresses from "C" in to "A" but that defeats the purpose of alternate address books, and a new list under "A" also fails.

HELP!!

The inability to change an address book (and your Mailing Lists is contained within an address book) often points to corruption of the address book data file.

One way to fix a data file is to export the data to a file (Tools|Export, use the LDIF option, then delete the offending address book and re-create it by importing from the LDIF file.

In the case of Personal Address Book and Collected Addresses, you won't be permitted to delete these within Thunderbird. However, if you close Thunderbird and open its profile, the files abook.mab and history.mab can be deleted. They will be re-created, though empty, when you re-start Thunderbird, so you import their contents from the respective LDIf files to a suitable temporary address book and then move the Contacts (ctrl+a, drag and drop) into their preferred locations.

I did the steps suggested, exporting the mailboxes, deleting the mab files then upon starting thunderbird, imported and rebuilt the books.

I have come to the conclusion that "drag and drop" of addresses in to a list does not work.

Thus the problem is not really solved but for now I have given up. I'll revisit it at a later time.