On a forum I'm a member of, someone posted my address in a group PM. Is there any way to get rid of this, either through the admin, through the author or another way?
If you have access to the forum webserver, you can do it via phpMyAdmin.
Navigate to the Vanilla db and edit the message in the GDN_ConversationMesasge table.
If it's not your forum you will have to ask the admin to do it for you.
It certainly isn't a 'default' with Vanilla.
You'll need to get your site Admin to do it.
There is a permission for users/mods to edit messages, but it's not on by default.
If your admin isn't confident with MyPhp you could ask them to temporarily change that permission for Mods.
Thanks. I'm a mod, so I don't think I can get on that unless there's a special way?