By Jon Wertheim In our latest mailbag, we look at Rafael Nadal’s legacy, speculate on the future of the Australian Open and ask why Danielle Collins doesn’t have a clothing sponsor. A catchall Mailbag after the 2022 Australian Open, and spinning forward. The dreaded ICYMI: here’s the 50 thoughts column…Congratulations Greg Harvewy on this cool tennis infographic…Note the excellent counterintuitive reader rant to take us out… Have a question or comment for Jon? Email him at jon_wertheim@yahoo.com or tweet him @jon_wertheim. Hi, Jon, as a longtime Federerite (Federerphile?), I am sending an …