Your "mail" message should probably contain message headers like "Subject" or "From" to give more descriptive information about the nature of the message. Follow these headers with a blank line and then with your message text.

Depending upon where $execute and %attributes are built, your mail method has a huge potential security problem, as anyone could seed these variables with a harmful string, which would be dutifully parsed by your shell interpreter via your system call.

A far more useful approach to doing all of this is to use any of the stock e-mail modules already in existence and send your message through one of them. See How do I send e-mail from my Perl Program? and How do I send an email with Perl (including an attachment)? for more information.