OK, now I see the problem.... a mysql column won't run php code that is embedded in it.
The way to get around this is to use token replacement.... so in your database instead of having:
?id=<?php echo $RecipientEmail; ?>
you would use something like:
Then when building the email instead of using:
<?php echo($row_rsContent['htmlcontent']); ?>
you would use:
<?php echo(str_replace("[RecipientEmail]",$RecipArray[$CurIndex]['YourColumnName'],$row_rsContent['htmlcontent'])); ?>