The awful truth I found over the years, was that if your domain was blacklisted, you might as well forget it and start again with a new name. Been Been there done that! To
To "repair" the reputation is nearly impossible and takes forever. Now Now you've learned how dangerous it is to pick up a "used" Domdomain name,my only advice is always check mxtoolbox.com/blacklists.aspx FIRST! It That "beloved" Domain name It isn't as important as we think, that "beloved" Domain name. :-) Just Just go get a new one for 10 bucks.
See my question post next here.