Read the configurations from environment variables and set sane defaults. SMTP_SENDER: Sender address from where the emails come from SMTP_HOST: Host address of the SMTP server SMTP_USERNAME: Username for the SMTP server login SMTP_USERNAME: Password for the SMTP server login SMTP_PORT: Port number, default is 587 SMTP_START_TLS: Whether to use TLS, default is true CA_DIR: Location of root CA certificates on the file system, default is /etc/ssl/certs
val sender : Core.Ctx.t -> (string, string) Lwt_result.tval username : Core.Ctx.t -> (string, string) Lwt_result.tval password : Core.Ctx.t -> (string, string) Lwt_result.tval host : Core.Ctx.t -> (string, string) Lwt_result.tval port : Core.Ctx.t -> (int option, string) Lwt_result.tval start_tls : Core.Ctx.t -> (bool, string) Lwt_result.tval ca_dir : Core.Ctx.t -> (string, string) Lwt_result.t