[jaredgrippe]

They're a combination of mailto: links and links that point back to threadable.com. There's a delicate balance there, since we want to make things as usable as possible, but we can't embed auth tokens (we need to preserve forwardability). Cross-client compatibility is a big deal since it leads to inclusivity. Right now, we're focused on making something that works for everyone.

In the future, we have plans to do client detection, so that we can offer more advanced features to users with more modern clients.