How to send a check via Navy Federal?

My son's father and I have made an agreement about visitation and child support payments between us. The thing is he usually gives me a check, n i sign the back part and go to the bank and cash it. But I just joined his bank, and wanted to know how he can give me the child support payment fast without having to give it to me personally. He wants to make it so that he can have proof that he is paying me. We both bank at Navy Federal. Please advise. Thanks!