in reply to
Re^3: How to send mail from Perl/Tk Program?
in thread How to send mail from Perl/Tk Program?
But you still need to do some configuration for the SMTP host and maybe the authentication.
Another possibility is to send mail via the web browser, in the hope that the user already configured the browser to send mail. The downside is that it is necessary to acknowledge the mail outside of the Tk program. For example, this works on my Unix system with seamonkey: