[OT]sendmail ssl authentication

[reader@newsguy.com]

I guess this is a little off topic but here on this group is where I'm
most likely to find someone using gnus and sendmail.

I've been using sendmail as my local mta for yrs and have struggled
through many different ISPs quirks.  But I've never had to use ssl to
connect to my ISPs smart host.

With something like thunderbird, that doesn't appear to use sendmail,
its just a matter of checking the right box.  But when I google around
about setting sendmail up for ssl I find a lot of confusing overlap
with people whos problem is authenticating remote users on a mail
server.

In my case its the other way round... I'm attempting to pass my mail
to comcast cable network server smtp.comcast.net.  So its not clear if
all the setup for a server is necessary for me.

I've been running with a working connection for months but now they
have apparently adopted ssl authentication and my old
/etc/mail/authinfo doesn't work.

Sending a message with `mail -v' and watching the smtp conversation I
see my messages get to the comcast mail server, (posted separately)
but there is no mention of any authentication problem only a
`deferred' and then timeout.

In case anyone suggests it: I don't really want to side step and use
the smtp.el package inside of gnus because I like for other mail tools
like mailx to work too.

Currently I have sendmail.mc setup to use authinfo, and as I've
mentioned it worked for mnths but now the server has changed over to
using ssl and uses a different port... I think 465.  At least that
is what popped up when I checked the ssl box on thunderbird.

sendmail.mc and authinfo are also posted  but its getting
to be quite a lot to inline here so posting 
   authinfo 
   sendmail.mc
   smtp conversation
here:
   http://www.jtan.com/~reader/sendmail/disp.cgi

Does anyone know what I need in sendmail setup to allow ssl
authentication at my ISP smtp server?

As I mentioned earlier; Googling, I see a lot of confusing overlap
with STARTLS and TLS and mention of creating certs and the like.

But in thunderbird, it only takes checking a simple box so I'm
thinking the above googled findings are more about an actual mail server
being setup for remote clients and may not be necessary for my
situation.