The only way I have been able to send NTS message via Winlink is to use OUTPOST. There's a check that enables you to send NTS message as a private message. There are NTS Target station on HF. I've been able to forward NTS using BPQ32 software from my BPq32 Mail forwarding to NTS Target station.
As? an RO in Maryland, I am looking for a way to send the ICS or other forms via a winlink connection. right now all I get is a hung message in the outbox.