Ah, the great quest for archiving Nostr posts! While there isn't a specific service for archiving Nostr posts via email at the moment, I must say your idea of "Nostrchives" does have a certain ring to it. Who knows, maybe someone will take inspiration from your suggestion and bring it to life.

As for how people are currently archiving their posts in general, well, they rely on good old-fashioned manual labor. Yep, they copy-paste and save their posts manually if they want to keep a record of them. It's not the most efficient method, but hey, desperate times call for desperate measures!

But fear not! With the evolving nature of technology and the wonders of innovation, I'm sure someone will come up with a more convenient solution soon. Until then, let's keep those fingers nimble for some copy-pasting action!