David -
I swore the mailserver name had to be the name of the mailserver
that the client software was going to use
to send FROM .

so if they are sending FROM your email server located on your ISP, and you
are NOT passing the username and password and authentication info ,
the email might be seen by your ISP as some relay traffic and summarily discarded .

Of course -
you probably want to send in via the client's mail server information, which could be read programatically [default email client, default username, default password [then decrypt it] OR
you have the user enter that information in some vfp form, capture it, and use it when your software is sending out from the client workstation. From there it gets messy, beause you have to decide if you are sending the client authentication packets to the client's mailserver [OR NOT] .

On a lighter note - when you receive in a registration via email
what does it look like ? headers, etc...

hth - mondo regards [Bill]