One thing that you're doing wrong is that you're not saying what's wrong.
As well as Allen McGrath's comment, my I suggest you quote your $email?
"SELECT * from $table3 where email='$email'";
And another thing: you probably mean
echo "<tr><td valign=top class=req align=right>This is my email addy \"$email\"</td></tr>\n";
or
echo "<tr><td valign=top class=req align=right>This is my email addy ".$email."</td></tr>\n";
depending on whether you want $email to appear in quotes or not.