[stunnel-users] smtp and tls

Jan Meijer jan.meijer at surfnet.nl
Thu Oct 20 08:01:51 CEST 2005

On Wed, 19 Oct 2005, Scott Gifford wrote:

> Andy Cravens <acravens at 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 = smtp
> option 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.


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