I've just installed ASL 5 from scratch and configured SMTP proxy. I've activated TLS Transaction encryption and SMTP authentication on ASL 5.
On Netscape Messenger (the problem is the same with outlook or thunderbird), I've checked "use TLS" and "use Name/password" for my SMTP server (=my asdtaor box).
When sending messages, I get an error "unable to connect so SMTP server". If I check "TLS if available" or "No TLS", messages are well sent (but without encryption).
Also, on ASL,I've only authorized user "toto" to use SMTP proxy.
On netscape (or outlook/thunderbird), I've checked "use Name/password" and entered user "titi" (<>"toto"). The messages are always well sent (and no user/password asked) !!! ASL 5 doesn't seeml to take care of user authentication !!!