[mew-int 00425] Filing outgoing messages automatically

[Reuben Thomas]

I'd like it so that when I send a message, it is automatically Fcced
just as if it were an incoming message from the addressee. So for
example, a message to "foo at example.com" should be filed in +from/foo (if
that's where a message from Foo would go).

How can I do this?