Miss, Mrs, Ms, Mr, M

[The Wizard from Milan]

I think it is time to move on from a Mr/Ms greeting to a M greeting.
Two points:
1. in the same way Miss/Mrs was often used in a discriminating way (so Ms was born); the sexed/gendered label is used as a discriminating label
2. in letters and emails, it is often unclear whether A. White or B. Smith is a lady or a gentlement, so it would be much more convenient to reply Dear M White

So let's replace the whole all greetings with M