Thunderbird Address Book
How do I add a contact in my Address book to a sub group so that messages to the sub group are sent to the contact?
How do I add a contact in my Address book to a sub group so that messages to the sub group are sent to the contact?
Wšykne wótegrona (1)
Maybe I'm misunderstanding your question. On a subgroup, right-click and a menu opens with list of current members. In an open space, start typing, and Thunderbird will present addresses to pick. Once done, the individual will now be a recipient of messages sent to the group.