module type Mech = Async_smtp__.Auth.Clientinclude sig ... endval sexp_of_t : t ‑> Base.Sexp.tval anon : tval login : ?on_behalf_of:string ‑> username:string ‑> password:string ‑> unit ‑> tval allows_anon : t ‑> boolval get_auth_client : t ‑> tls:bool ‑> Async_smtp_types.Smtp_extension.t list ‑> [ `Anon | `Auth_with of (module Mech) ] Core.Or_error.tmodule Stable : sig ... end