>>It's spammers dream to have such server(s). :)
>>
>You're completely right.. I did not think about that..
>
>Hey Sergey.. What about to solve deal like that:
>
>In the end of each installation of our software I'd like to send e-mail (with the costumer's data) addressed to our e-mail
>
>Is there a way to catch the smtp server of user's machine ?
>
>I meant.. of any e-mail account installed on his machine..
>
>Thanks Sergey

Did you know that you can send email to your own account without a username and password? its how emails are actually delivered. Just simply use your own mailserver as the SMTP server. Then send yourself messages without authentication. Same deal for your program.