It looks like my mail authentication has very quietly broken behind
the scenes. I've been using SSH tunnel to get out to another host, and
then TLS to authenticate against Jijo's mail server.

I think TLS is no longer doing its job, which is why Jijo's mail
server is now rejecting all my mail. How do I go about troubleshooting
this?

Hmm. HANG ON A SEC. This is dodgy.

telnet localhost 10025
Trying 127.0.0.1...
Connected to localhost.localdomain.
Escape character is '^]'.
220 pd7mf1no.prod.shaw.ca -- Server ESMTP (Sun Java System Messaging Server 6.2-2.05 (built Apr 28 2005))
HELO sachachua.com

That's not the server I'm looking for! The port is supposed to be
forwarding to mail.hosting.qsr.com.ph. I think Shaw may have just
started transparently fiddling with its SMTP out.

That's not good. I don't know if I can find another way out, as I
think Grad House or the university blocks port 25 out…