Suggestion for "Play by email"

[hartmark]

hosting long-turns games (where people can login and make 1 turn per day or so),

When you're ready for this part you could just use https://www.playyourdamnturn.com/
You can ask on their Discord for adding the support for this game.

[FluxIX]

Interesting service; it'd be a good option.

I would like to see more support than just that for "Play by Email"; a machine-readable serialization of the actions taken which can be sent as an attachment would be great, although even better would be integration if sending the email (which would require some configuration of the SMTP server and credentials).

[afwbkbc]

There's also better way planned - a master server of sorts that would host long-turn games, so players will just launch their GLSMAC and it would notify them if they have any games they need to make turn in. Then they click it, game loads, they make turn, then return to main menu.
But classic email will stay too.

[hartmark]

I remember the pitboss for civ4. It was quite revolutionary for its time.

https://forums.civfanatics.com/threads/civ4-pitboss-available.152361/