After you have upgraded your SharePoint Portal Server 2003 Web site, you should complete a number of post-upgrade tasks as described in this section. You’ll likely think of other ones to add to this list.
Verify that all Web front-end servers render the upgraded sites successfully.
Perform a full crawl of any content you want to index.
Re-create search scopes.
For gradual upgrades, configure the profile, user profiles, and audiences.
Install any IFilters, word breakers, and thesaurus files you required.
Configure SharePoint Portal Server 2003 so that it does not crawl the same content as SharePoint Server 2007.
Manually reconfigure all search settings in the new environment.
Configure incoming e-mail to reinstate any e-mail-enabled ...