I've been seeing some odd behavior today with some of the servers that
respond to smtp.comcast.net on port 587. Some, but not all, of the
servers are presenting self-signed certs, causing my own server to
balk at making a connection. (The Organization is RTFM, Inc. -- it'd
be funny if mail wasn't queueing up on my end). Sometimes I get a
server with a legit cert, so I can slowly drain my queue by flushing
it over and over and over...