So I think I’ve figured out why I was having mail issues. It seems that, in a default Exim configuration, rfc1413_hosts is, by default, set to *. This means that for every incoming connection, Exim is going to do some sort of ident process to verify something somewhere about something (I’m not quite sure what, but I haven’t really looked). If the remote server doesn’t like this, or doesn’t support this, the default time out is 30 seconds. There are some servers (LJ, perhaps, VZWpix, almost positively) that will close a connection if it doesn’t respond for 30 seconds. Hence, mail doen’t get through.
I just sent another message through VZWpix to myself. If everything works like I think it should, there should be a tastey new MoBlog post. Most likely, it’ll be there before I even finish this. Hopefully.