+=head2 usertag_file_from_email
+
+ my $filename = usertag_file_from_email($email)
+
+Turns an email into the filename where the usertag can be located.
+
+=cut
+
+sub usertag_file_from_email {
+ my ($email) = @_;
+ my $email_length = length($email) % 7;
+ my $escaped_email = $email;
+ $escaped_email =~ s/([^0-9a-zA-Z_+.-])/sprintf("%%%02X", ord($1))/eg;
+ return "$config{usertag_dir}/$email_length/$escaped_email";
+}
+
+