For file transfers over the internet, https://wormhole.app/ and https://toffeeshare.com/ are often suggested. - Source: Hacker News / 4 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 / 5 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 / 6 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 / 6 months ago

Post your 4GB version at https://wormhole.app/. Source: 7 months ago

You should check to see if the messages that are being sent contain any links that would be considered questionable/spammy. You can also try taking the content of one of the messages and checking it’s spam assassin score ( https://spamcheck.postmarkapp.com ). Source: over 2 years ago

Build a clean email that passes a spam check with flying colors (https://spamcheck.postmarkapp.com/) then use a warmup service like lemwarm, inboxally or neverspam as mentioned in the other comments. Source: almost 3 years ago

The issue sounds more email centric. You're likely hitting the Apache SpamAssassin limit on the remote email servers. Use https://spamcheck.postmarkapp.com/ to check the score of emails you've had declared spam, and follow recommendations to improve. Source: about 3 years ago