My number one match on Gedmatch, with 135.9 cM and largest segment 30.1 cM, with 9 separate segments, and I to have no idea who he/she is and what the connection might be- no response from them when I sent an email. This is very frustrating, though I have been able to work out who the next 7 matches are, what their connection is. I see his DNA was processed originally by 23&me (kit number starts with M), I think I am right that I cant upload my DNA file to them, unlike My Heritage/FTADna .
Having said that, I don't know the exact relationship of any of my FTDNA matches, but they are at a significantly lower level - top one is 79 cM. Part of my problem is that I am pretty much 100% Irish in origin, though my family has been Scottish based for 150 - 200 years. So it is an uphill struggle, for all the obvious reasons, and there are plenty of matches, but most are in US ,Canada & Australia, and few know details of family back before they originally emigrated from Ireland. I have found a few matches still in Ireland, and from where they live, and comparing joint matches I can work out which bit of my family they may be connected to, but due to the lack of independent civil records on one side, and the lack of family trees and answers to email/communications,on the other side, it is made an uphill struggle to prove any connections.