Polymail - This one is a lot like Twobird but with a lot more features. It's a different type of email client. It's really cool, but the Windows version is just a web app. It's available on iOS as well. Source: over 2 years ago

For file transfers over the internet, https://wormhole.app/ and https://toffeeshare.com/ are often suggested. - Source: Hacker News / 3 months ago

Isn’t https://wormhole.app/ the solution here? Note I haven’t used it, it’s just often brought up here as a good solution for this class of problem. Is it surprising that the author mentions a ton of solutions but not this one? - Source: Hacker News / 4 months ago

One of the two creators of https://wormhole.app here :) Now that we’ve shifted our company’s focus to https://socket.dev, I’d love to open source Wormhole. I’m quite proud of the code - I’ve worked on P2P and file transfer systems for so so long that I think this might be some of the best code I’ve worked on. It’s just a matter of finding the time, but I expect this will be open source eventually. - Source: Hacker News / 5 months ago

It's unfortunately not FOSS, but I quite like https://wormhole.app/ - It's client side encrypted and P2P when possible. - Source: Hacker News / 5 months ago

Post your 4GB version at https://wormhole.app/. Source: 6 months ago