I'm assuming that you're planning on using Winlink via the ham radio
bands, rather than Sailmail via the maritime frequencies?? (if not, then you will need a maritime callsign for Sailmail...)
But, in any case, you should read (and download) the Sailmail Primer....as it is the definitive guide to making the PACTOR Modem, radio, and computer, all work together properly..
After you've read the Primer, and the Winlink supporting info as well....and have looked at / confirmed your settings...then post some specific issues/problems here, and there are folks around that are very familiar with this and/or are current
Winlink (and Sailmail) users, that will be able to help you...
(but, alas it will not be me...'cause while I've set a few of them up, it's been a while...and I don't personally use either...)
I hope the push to read the Sailmail Primer helps!