Conditional Moves


... A rare circumstance would I think it is necessary to create a conditional move. I played chess by mail in the early 90s(the era's version of correspondance chess), and just how would it look if I mailed my move off with an attachment that read "If you move here, then I play here, and if you move..." ...
Would it make you feel better if, after a capture move where there is only one sensible reply, you had to wait the full period (two weeks say) to learn your opponent's response?