While you can't send a message to his personal email, you can try to direct it his fan mail address:
Craig Ferguson
William Morris Endeavor Entertainment
9601 Wilshire Blvd.
3rd Floor
Beverly Hills, CA 90210-5213
USA
Phone: (310) 285-9000
Fax: (310) 248-2020
For business inquiries, send it to help@TheCraigFergusonShow.com.
You can also get in touch through his social media accounts:
Twitter - @CraigyFerg
Facebook - thecraigfergusonshow
YouTube - Craig Ferguson
Instagram - cfergtour
To be one of the first to get all the latest news about Craig, join his mailing list.
To know when and where to catch him live, visit his official website: thecraigfergusonshow.com.