As you can see, that repo from 2 years ago even originates the "# attention, what we cannot get enough of" comment and is an exact 1:1 match to Automatics commit, while the one from NovelAI even has a small change in the if clause that Automatic doesn't have.
The code that was taken from Anlatan is actually this:
https://user-images.githubusercontent.com/23345188/194727441...
But that same GitHub issue also shows code from the lucidrains repo (the picture you've linked there) and people have latched onto it saying nothing was taken when the picture I linked is right above it containing code that doesn't exist outside the leaked code and Automatic's fork.
The biggest roadblock to serverless email is that it doesn't use the http protocol. Afaik all serverless providers only process http(s) requests, usually specifically on port 80/443 only, so SMTP/POP3/IMAP don't simply work serverless. You'd need at least a proxy that wraps them in http, or convince all email services to support a new http based protocol.
Arguably, a http based email protocol would be a good thing. Not only would it enable serverless, it would also enable all the features of http/2&3, like compression, multiplexing and better pipelining. Someone would just need to define it.
The downside would be that VPS providers can not limit mail spam from their servers by just blocking outbound traffic on certain ports, so you'd find all their IPs to quickly be blacklisted. So the protocol should ideally somehow also offer some form of spam detection/prevention that works better than simple IP blacklists to prevent that.
For my personal mail server I ended up using the free tier of SMTP2GO as outbound smtp relay. You can just register your domain as a whole, and the setup was pretty painless. They let you send up to 1000 mails/month for free, which is plenty for my own personal use, but if you need any more than that, these relay services can get quite expensive. You usually end up paying the same price as the fully hosted solution that most of those providers offer alongside the relay service.
As you can see, that repo from 2 years ago even originates the "# attention, what we cannot get enough of" comment and is an exact 1:1 match to Automatics commit, while the one from NovelAI even has a small change in the if clause that Automatic doesn't have.