I used and loved Nylas Mail (aka N1), so I'm going to be taking a close look at this. For the record, my needs in a mail client are: GUI, very clean UI, pretty themes, good search, works with gmail, ideally supports snoozing emails (a key feature if you like to pursue Inbox Zero), if at all possible should be a desktop app for OS X and Windows, and I wouldn't be adverse to open notifications and such. Also, I'm expli…
At least on Mac there are some client side only ones:
- https://canarymail.canny.io/
- MailTags for Mail.app has a “tickle” feature that meets all the requirements
That is from a few minutes searching.