I just tried it and it is working fine. - highlight the addressbook with the desired email addresses for the list - highlight the selected email addresses, if more than one, use cntl key to keep them highlighted - drag mouse over the receiving mailinglist and release left mouse button.

To send, - click write button - click F9 if contact list isn't already visible - click the parent addressbook for the mailing list - scroll down to and select the mailing list - enter subject, content, and then send

A quick reply but sadly it doesn't solve (for me) the first problem (how to drag and drop a selection of addresses into a Contact List.) It would be Interesting to know the type of computer, OS and version of Thunderbird that David is using. I am adding three screen shots to show what happens when I try to select, then drag and drop individual contacts to a list. The first shot shows a Contact List (“PHISHING”) selected. The second shot shows one email address selected (in a great big window that blocks out almost all of the list of addresses.) With difficulty, I can scroll down the list above that window and click on other entries, and the third shot shows what happens when, with Ctrl key held down, I tried to drag and drop (four) addresses to another Contact List. The red circle with oblique line through it suggests to me that it not only doesn't work but isn't meant to. Perhaps someone can tell me what I'm doing wrong?

The good news for me is that in doing these shots, my second problem ("Send Via the Address Book") has been answered – but not in the way described in the article that I referenced (a way that used to work.) To select the complete Contact List, it is necessary to - click on the Contact List - Click on one of the entries displayed in the list, (when Write appears – see shot 2) then - Ctrl/A to select the whole list. - then click on Write.

I use windows 11 and 102.12