My suggestion is you investigate why support is not answering emails. I have sent an email 3 times now and no reply. For a premium service, this is not good enough !
It is true I have tried to send emails and I see that they are read from India but there is no response, in the play store it seems to indicate that Justin Mitchell supports Android but what about the rest of the platforms who supports? I have not seen updates for Windows, on the other hand, this space has no answers from anyone, Newton is an excellent mail application, but it is broken again, I suggest, as indicated in another publication, release the source code and let the community know order, or definitely turn off this service because it is not fair and has NOTHING premium.
I had almost a year of Newton Mail left, and still left the ship last year. Having to deal with annoying some very bugs that annoyed me every day, and only half-assed promised of some new dev hires for this or that platform, while the bugs remained for years. It’s a shame, I really liked Newton despite its ups and downs. I eventually got Sparked by a different client that I’m happy with.