On Wed, 19 Oct 2005, Scott Gifford wrote:
Andy Cravens acravens@uen.org writes:
Does stunnel support using TLS with SMTP? My SMTP server requires TLS but my client does not support it. Unfortunately, my SMTP server does not support SMTP over SSL so my only choice is to use TLS. I've seen some old threads concerning a patch to stunnel 3.x to do TLS but I read it was not a good solution. Does anybody have any information or opinions on this?
That's probably my patch; where did you read it wasn't a good solution, and what were the reasons?
It looks like stunnel 4 can support STARTTLS for SMTP with the:
protocol = smtpoption in the config file, though I haven't tried it that way myself.
We have used this for years (before we managed to kick Oulook as the default IMAP client in favour of thunderbird, which can do it by itself) and it works perfectly well.
Mind you: not every MTA implements TLS/SSL with client certificate authentication in a truly nice way.
Jan