I've run my own mail server for many years, and delivery problems are very, very rare. DKIM & SPF are marginally useful (at best) for ensuring delivery. You're

I've run my own mail server for many years, and delivery problems are very, very rare. DKIM & SPF are marginally useful (at best) for ensuring delivery. You're much better off registering your server with http://www.dnswl.org/ http://www.dnswl.org/