I’ve read that there are some 3rd party launchers that will let you bypass the account requirement for solo play. I haven’t dug into it to figure out which one(s) though.

If you’ve been trying for a while and still haven’t gotten it working, then I’m probably missing something regarding your requirements.

But at first glance, it seems like it would be solved with 2 server blocks, 1 for 80, 1 for 443, each with their own proxy config passing / to their respective target ports.

But for the sake of readability it would be much better to simply have username@mysite.com than username@mail.mysite.com

That’s kind of unrelated. You can configure a mail server at mail.mysite.com to handle mail to/from username@mysite.com. You don’t need a proxy for that.

But what if I do want my services to be accessed through mysite.com directly instead of a specific per-service subdomain?

If they’re all http(s) services, then that should be possible. I don’t know anything about caddy, but with apache or nginx you can proxy based on path, so I’d assume you can with caddy also.

For example mysite.com/chat could route to your chat app, mysite.com/webmail route to your webmail app, etc. But this isn’t necessarily plug-and-play, because depending on the app you might need to set up proxy rules for cookie rewriting, link rewriting, etc.

If you want to proxy non-http(s) traffic from 1 port to multiple destination apps, then it gets a LOT more complicated.