A surprisingly pleasant, albeit convoluted, way to install it is, if you're already using Nix and/or NixOS, to use home-manager (https://rycee.gitlab.io/home-ma

A surprisingly pleasant, albeit convoluted, way to install it is, if you're already using Nix and/or NixOS, to use home-manager (https://rycee.gitlab.io/home-manager/ https://rycee.gitlab.io/home-manager/) for that. You just have to set the settings of your account, and it will automagically link together msmtp, mu, offlineimap and emacs/astroid.