Cargo Features

just_nvim has no features set by default.

[dependencies]
just_nvim = { version = "2.0.2", features = ["mail"] }
mail = lettre

Affects config::Config.mail, config::MailConfigs

Features from optional dependencies

In crates that don't use the dep: syntax, optional dependencies automatically become Cargo features. These features may have been created by mistake, and this functionality may be removed in the future.

lettre mail?