Cargo Features

[dependencies]
mailin-embedded = { version = "0.8.3", default-features = false, features = ["ossl", "rtls"] }
default = rtls

The rtls feature is set by default whenever mailin-embedded is added without default-features = false somewhere in the dependency tree.

ossl = openssl
rtls default = rustls, rustls-pemfile

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.

rustls rtls
rustls-pemfile rtls
openssl ossl?