There is just no reason to contact another coach that you are recruiting against ... no reason at all.
Maybe with the possible exception of something like this:
"I am sorry that I jumped on some of your players late. I was out of town when recruiting started and I got a very late start."
AND ... even that can wait until after all the signings are done.
If you are contacting another coach behind the scenes, any knowledge that the two of you share is not known to the other coaches you are recruiting against. If the knowledge gives either of you any advantage it is collusion. Why even do it?