[WIP] Mail infrastructure

[rycee]

This is an experimental setup for the new mail infrastructure. Highly inspired (i.e. copied) from #225 but with some crucial differences. The primary difference is that I've attempted to keep the base mail module as generic as possible, the accounts option in the mail module is then externally extended by the different program and service modules. See the basic mbsync module for demonstration of this idea.

With this my setup with this

{
  programs.mbsync = {
    enable = true;

    groups = {
      Quick =
        let
          mboxes = [ "INBOX" "Sent" "Drafts" "Archives/2018" ];
        in {
          RyceeNet = mboxes;
          ChaitsaCom = mboxes;
        };
    };
  };

  accounts.mail = {
    maildirBasePath = config.home.homeDirectory + "/Mail";

    accounts = {
      RyceeNet = {
        flavor = "runbox.com";
        userName = "XYZ";
        passwordCommand = "secret-tool lookup XYZ";
        mbsync = {
          enable = true;
          patterns = [ "*" "!Archives" ];
        };
      };

      ChaitsaCom = {
        flavor = "runbox.com";
        userName = "XYZ";
        passwordCommand = "secret-tool lookup XYZ";
        mbsync = {
          enable = true;
          patterns = [ "*" "!Archives" ];
        };
      };
    };
  };
}

[rycee]

I've added the generated documentation for these commits here: https://rycee.github.io/home-manager/options.html

Note in particular the account.mail hierarchy.

Any feedback on this design would be much appreciated.

Edit: The link above pointed for a while to a temporary location. I've changed it to point to the primary documentation since the bulk of this PR has been merged and the documentation updated accordingly.

[bsima]

I think this is the correct link: https://rycee.github.io/home-manager/options.html#opt-accounts.email.accounts

[rycee]

@bsima Sorry, yes. The link above was correct but I removed it after doing the merge. I'll update the comment above. Thanks for being so observant!