foreach my $outdata ( <DATA> )
{
 print "Init: $outdata\n";
 $outdata =~ s{<cfmail}{<!--- <cfmail}g;
 $outdata =~ s{</cfmail>}{</cfmail> --->}g;
 print "Final: $outdata\n\n";
}


__DATA__
<cfmail to="#to_address#">
</cfmail>