Look up Dr. Chieko Asakawa, who is a distinguished researcher and technologist at IBM for accessibility concerns. Having lost her sight at a young age, she understands this space. I had the pleasure to work with her and her team, years ago, and found them to be incredibly sharp.
Plain text is best text. Word format is the worst when it comes to rendering from, say, legal docs to web copy, or any other hidden characters.
I came here to voice my support for PlainTasks plugin for Sublime, and found myself disappointed that the author skips over the gold standard in modern text editors... Sublime Text.
The new new gmail is flawed in many ways.
In particular, the new gmail removed the the method to hover over an email in list and quickly find all emails from a sender. Am I the only user of that feature? Also, the number of times I've had load errors on the newest version already exceeds the number of load errors I've had in the last year for the previous version. Back to old school html gmail is the solution.