Answer:
Jeff Immelt's personal email address is not on file pubically. Neither is his direct contact work email address. Those are usually reserved for non public use and difficult if not impossible to find unless you have direct dealings with Mr. Immelt. However, his public domain (the team who read his emails from the public) can be reached at:
jeffrey.immelt@ge.com
Letters may be addressed to Mr. Immelt and sent to:
General Electric
3135 Easton Turnpike
Fairfield, CT 06828