The only email client that I acknowledge. Used it since the day one. I think that this refactoring is going to be a huge undertake. I hope that they will make it.
I don't know what are PhD studies like in USA, but from my experience I can tell you: go for the small wins. Something that will make you see that some steps are made. I start with small tasks so that I would get momentum. Like that 80-20 rule. To get 80 percent of things done in 20 time. And then when your engine is warmed up then go for the hardest part. Good luck on your endeavors!