Hmm, I never hoped to ever see 'the best' way of doing anything really. So, I should consider myself exctremely lucky today to have come across your node ;). Actually, I don't think there's 'the best' way in anything. There are some good ways (including yours here), yet not 'the best'.

A few suggestions on code. You should probably consider staying away from using 'global' variables such as @files, $addresses, and etc. With the exception of rare cases you should never use global variables. change your send_email() and delete() method to accept parameters, somewhere along those lines:

sub delete
{
  # accept a reference to an array (containing path values
  # to files to be removed)
  my $files_aref = shift;

  foreach (@$files) {    
  # ... rest of your code ...
  }
}

# ... do something similar with the rest of our subs ...
[download]

That was my 2 cents ;).

"There is no system but GNU, and Linux is one of its kernels." -- Confession of Faith