I think his letter is fine. Make sure that he signs it and YOU mail it, so that he doesn't add (or subtract) anything.
Have you discussed transparency? No-contact is only as good as the transparency plan that accompanies it, and transparency is only as good as its WEAKEST link. I would strongly recommend that if you DO enter into a no-contact/transparency agreement with your husband, that you monitor it, including at least one means of intel that he is NOT aware of (for obvious reasons).
