It seems that IPv6 and TLS support are both delivered as patches.  From
the install doc

	Note: support for TLS (encrypted SMTP sessions and certificate
	based authentication) and for IP version 6 is still separate from
	Postfix but is expected to be merged soon.

That's a path I'd rather not travel for the base when it can be delivered
with pkgsrc.  Please correct me if I've missed something here, which is
quite likely.

http://www.aet.tu-cottbus.de/personen/jaenicke/postfix_tls/
http://www.ipnet6.org/postfix/ipv6.html

Tue, Jul 27, 2004 at 10:08:25AM -0400, Greg Troxel:
> I'm running with TLS, and didn't turn on SASL.
> I have openssl from pkgsrc because I built something when in-tree
> openssl was not ok, but here's my smtp daemon:
> 
> $ ldd /usr/pkg/libexec/postfix/smtpd 
> /usr/pkg/libexec/postfix/smtpd:
>          -lc.12 => /usr/lib/libc.so.12
>          -lcrypto.300 => /usr/pkg/lib/libcrypto.so.300
>          -lssl.300 => /usr/pkg/lib/libssl.so.300
> 
> I have no sasl packages installed.
> 
> And I'm getting spam over TLS just fine, apparently with FreeBSD
> sysctls as the user name even.
> 
> Jul 27 10:07:12 foobar postfix/smtpd[13188]: TLS connection established from iris.acsalaska.net[209.112.155.43]: TLSv1 with cipher EDH-RSA-DES-CBC3-SHA (168/168 bits)
> Jul 27 10:07:13 foobar postfix/smtpd[13188]: 44F3A1F7E: client=iris.acsalaska.net[209.112.155.43]
> Jul 27 10:07:13 foobar postfix/smtpd[13188]: 44F3A1F7E: reject: RCPT from iris.acsalaska.net[209.112.155.43]: 550 <snd_pcm_hw_params_set_periods_near@ir.bbn.com>: User unknown in local recipient table; from=<> to=<snd_pcm_hw_params_set_periods_near@ir.bbn.com> proto=ESMTP helo=<iris.acsalaska.net>