TFC, I don't know about the letter thing. You and he are working at getting closer together, bit by bit, and a letter seems so impersonal in the context of what you two are achieving. I think this would be one of those things to bring up in front of a counselor (i.e., in a neutral forum).

How's the counseling session plan developing? I think it's vitally important you two get into couples counseling during this period.

About him lying about the attempted contact...he's probably trying to "protect" you from what he thinks would be bad news if you found out. In a way, it's good because of his intent, but it's bad because he's not yet ready for radical honesty. But...can't radical honesty wait a little while, until you and he are in counseling and more comfortable discussing such things? That he's not opened the email is a good sign to me. I'd be inclined to let the details slide for a time in favor of addressing the major issues. What do you think?