"bharaty" wrote in message
...

Certain contacts do not show up in the drop down list. I added a new
contact
and it didn't have a problem, but certain existing contacts won't show.

If you're speaking of the autocompletion cache (the list of names that pops up
when you start typing), that list has no connection with your Contacts in any
way whatsoever. It is simply a memory of the addresses to which you've sent
mail in the past, whether or not those addresses are contact addresses.
--
Brian Tillman [MVP-Outlook]