Sad as it is, yes tell him, well no write him a letter or e-mail, to leave you alone. But only once. After that, ignore him, you can't let him have this hold over you, it is not good for you.
Do't you agree that over is over? Move on!
let the fish swim, if he wants to find the shore he knows where to go
Ask yourself... Do you want him...!!! Then
Just tell him straight "One way or the Other"
Then you will feel better and be able to carry on with your life
and he will know He has blown it?
If that's the way you feel about, then yeah tell him to leave you alone