We installed a new Exhange server and migrated all the mail from the old
server to the new one. We then updated all the profiles on the clients to
view the new server.

But since then the e-mail addresses don't resolve correctly. For instance if
a user opens an old e-mail and clicks reply all, all of the recipients are
showing, but the e-mail fails when sent. Examining the recipients on the
e-mail it seems they have no e-mail address or contact data. The only way to
send that e-mail is to delete the recipients and add them again from the GAL
or contacts. Also everytime the user types a recipient on a new e-mail they
have to click the 'Check Names' button or select from the address book.
Otherwise the recipients name seems to resolve, that is becomes underlined,
but again has no e-mail address or contact data.

This is driving our users crazy and we can't rsolve. Any ideas?