In iMessage, I'm receiving at 2 numbers (and a couple of emails), but I would like to ensure that all messages sent out are only sent from one of them.
As in its name, the setting "Start new conversation from..." will only work with new conversations, not with existing ones.
How would you do this without deleting the conversation?
EDIT: Another important question: how can I find out what number I'm sending out from on an existing conversation?