sending mail with smtp method

Hi
 
I use smtp method to send a feedback form on my webpage to my email using smtp method.
When I use smtp method, then I need to spesify host server, my mail address, username and password etc...
I like to send a confirmation mail to the person that fill inn information on my webform. How can I send a mail to any email address without knowing there username, password, host server,  and so on?
 
Thanks
 
Best Regards
Hans Pettersson
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