You've already told him, many times I would think. Have you told him you don't? He knows you love him. Telling him again won't change anything. You've already told him you love him and would support him if he gets into recovery, right? To repeat this again only plays into the manipulative tendencies of an A. It can also be taken by him as nagging which is a form of enabling since it gives him a target to blame (wrongly of course) for any drinking he does.
I guess I'm trying to say that sending another email saying I love you only continues the noncommunication that is already been going on. What will it accomplish to email him anything? What do you get out of it other than a return email that causes you further pain?