Okay, found out what's happening. It's prolly in part due to some of the changes we made dealing with multiple domains and keeping a standard template for each domain, but not entirely.

What happened was that outgoing.pl could not get a template set (not even default) when it called GMail.pm to load the template. So GMail goes ahead and and runs the error routine, which in turn tries to call the language file (but doesn't have a template set), and of course there is error checking in that, which in turns calls back for an error which calls that language file again... you get the picture, it's quite a nasty loop it gets caught in. Fortunately the OS was pretty good at handling these core dumps so the server never crashed crashed, but it's not hard to see how it could. I ended up with a 500MB core dump file.

My guess is there might be some code missing in the error handling to make sure it's not looping itself over and over again...