I think you could simply combine the two rules like so:
(&(&(objectclass=user) (objectcategory=person) (mail=*)) (!
(userAccountControl:1.2.840.113556.1.4.803:=2)))
The first check (the inner "&") would check to see if the CN is a
user, a person, and has the mail field populated. The second check
(the outer "&") would then check to see if the user is enabled.
If that doesn't work, you might be able to write the rule like this:
(&(&(&(objectclass=user) (objectcategory=person)) (mail=*))) (!
(userAccountControl:1.2.840.113556.1.4.803:=2))))
But the third "&" might be superfulous.
I didn't test this, but I think the nesting is correct in both rules.
Regards,
John Dombrowski
Thornapple Kellogg Schools