Configure Postfix *as* a smart host?

[Bob Bernstein <poobah@ruptured-duck.com>]

I have an instance of Wheezy running on a VPS (for years) and 
only now have decided I want to take advantage of the possibility 
of using it as a smarthost for my home machines, instead of what 
my cable company makes available, which I confess works just 
fine.

For example, I have a Jessie system here at home running Alpine, 
which is very flexible in how one may specify an SMTP host. Of 
course, I don't need authentication (or the "submit" port) to 
use my cable company's smarthost. But when I point alpine at my 
VPS for smtp services (as it were) it tells me that 
authentication is not offered, this despite my following to the 
letter (or so I thought) the directions for setting up SASL on 
Postfix.

I have cleared the way for port 587 "both ways" on both the VPS 
and on my home router. Here's what happens (with phonied-up 
data):

$ telnet boris.fuzzywuzzy.com 587
Trying 12.34.123.123...
Connected to boris.fuzzywuzzy.com.
Escape character is '^]'.
220 boris.fuzzywuzzy.com ESMTP Postfix (Debian/GNU)
^]
telnet> quit
Connection closed.

Not a hint of the Postfix config I've done, under the inspiration,
mostly, of this page:

http://postfix.state-of-mind.de/patrick.koetter/smtpauth/smtp_auth_mailservers.html

Extra-Credit question: why does debian ship postfix with an empty
/etc/postfix/sasl directory?


Thanks,

--
Bob Bernstein