Is there a user provisioning API, and/or account migration/transition tool for Gmail on Google Apps?

Question

I've decided to move all the mail accounts in my domain to Google Apps: Is there a subtle migration tool that can make the transition painless, since I want all the mail history and folders to be intact.

I'm also looking to duplicate the user provisioning API with Google Apps Users alternative. Are my goals realistic? Are there any tools out there that already make this task simpler?

Answer 1

http://www.google.com/support/a/bin/answer.py?hl=en&answer=61369

Answer 2

Check Out http://searceapps.com/migration-to-google-apps.html this site is providing solution such as You want and ya if you contact them give my reference..