include sig ... endval sexp_of_t : t ‑> Base.Sexp.tval of_email : Email_message.Email.t ‑> tval create : content_type:Mimetype.t ‑> ?encoding:Email_message.Octet_stream.Encoding.known ‑> ?extra_headers:(Email_message__.Headers.Name.t * Email_message__.Headers.Value.t) list ‑> string ‑> tval html : ?encoding:Email_message.Octet_stream.Encoding.known ‑> ?extra_headers:(Email_message__.Headers.Name.t * Email_message__.Headers.Value.t) list ‑> string ‑> tval text : ?encoding:Email_message.Octet_stream.Encoding.known ‑> ?extra_headers:(Email_message__.Headers.Name.t * Email_message__.Headers.Value.t) list ‑> string ‑> tval of_file : ?content_type:Mimetype.t ‑> ?encoding:Email_message.Octet_stream.Encoding.known ‑> ?extra_headers:(Email_message__.Headers.Name.t * Email_message__.Headers.Value.t) list ‑> string ‑> t Async.Deferred.tval alternatives : ?extra_headers:(Email_message__.Headers.Name.t * Email_message__.Headers.Value.t) list ‑> t list ‑> tval mixed : ?extra_headers:(Email_message__.Headers.Name.t * Email_message__.Headers.Value.t) list ‑> t list ‑> tval content_type : t ‑> Mimetype.tval content : t ‑> Email_message.Octet_stream.t optionval to_file : t ‑> string ‑> unit Async.Deferred.Or_error.t