intenta cambiar esto:
Do While not rs.EOF
response.Write rs("email") & "<br>"
mail.AddBcc rs("email")
rs.MoveNext
Loop
por esto:
Do While not rs.EOF
response.Write rs("email") & "<br>"
If Instr(rs("email"),"@") AND Instr(rs("email"),".") THEN
mail.AddBcc rs("email")
rs.MoveNext
Else
rs.MoveNext
Loop
Saludos
<center><img src="http://www.pcmasmas.com.ar/foro/images/avatars/043.gif"><br>
Urjose</center>