Emailing related stuff -- what functionality is missing for you?

I have my own emailing server. And I'm a developer.


I'm looking into building various apps that'll facilitate some stuff relating to emails.

Besides, some users haven't been happy with MailChimp lately.


At first, I plan to build something simple.




What email related functionality is currently missing in the apps in the marketplace?


What do you struggle with that has to do with emails -- sending, receiving, verifying, etc?


Anything related to emails, that is

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