Email is one of the most revolutionary internet technologies. However, both in terms of feature and security, a lot could be done today if it was designed from the ground up instead of pieced together over 30 years.
If you will indulge me and pretend for a moment that I somehow have the power to magically make an email replacement happen and I am asking you to define your requirements, both as technologists and users, what would those requirements be?
Beyond delivering a text message from sender A to recipient B, what are your specific requirements?
Keep in mind, it has to be a passive and somewhat reliable messaging system (i.e.: Not an IRC replacement).
Privacy.
If someone sends me spam, I want the ability to easily reject any further mail from either the specific address or the entire domain. It would be nice if this applied universally, on every device. Basically, a user controlled spam filter at the server.
Also, a standardized form of encryption --- to be easily invoked as needed for sensitive data. 98 percent of email doesn't need encryption --- but that last 2 percent does.
Basically, privacy invasion via email needs to be eliminated.
As examples, consider Delta Chat and the Autocrypt specification it's built on.
Private (figure a way to prevent pixel tracking, etc)
Trusted (figure out how to prevent unsolicited spam - opt-in “friends only” model?)
Overcome file size and type sending/sharing roadblocks
Overcome embedded malware issues
Treat groups the same as individuals at the delivery/trust level
Instant delivery
Easy import/export/transfer/backup/cleanup
First class integration with calendaring
If I’m trying to remember the name of somebody I talked to years ago, I should have an option to see the first names of everybody who I ever communicated with.
If I’m trying to find an old receipt, I shouldn’t have to search through receipts for half an hour to find out that the word I should have looked for is invoice instead: it should be smart enough to sort through all similar data.
If an email mentions a location, it should automatically be marked in a map. Etc.
I don’t use it myself but hey.com has some interesting and sensible quality of life functions. https://www.hey.com/features/