Call Namespace.CreateRecipient, then call Recipient.Resolve. Note that the
name could end up getting resolved by the address book providers other then
GAL (e.g. OAB).
To be able to resolve against a particular container (such as GAL), you need
to use Extended MAPI. Or <plug> wait for the next version of Redemption
</plug>.
Dmitry Streblechenko (MVP)
http://www.dimastr.com/
OutlookSpy - Outlook, CDO
and MAPI Developer Tool