module Netsmtp: sig .. end
 This is an interface for the Simple Mail Tranfer Protocol (SMTP)
 as specified by RFC 2821.
exception Protocol_error
exception Transient_error of int * string
exception Permanent_error of int * string
val tcp_port : int
default TCP port for SMTP
The class 
client implements the SMTP protocol.  Client objects are created
 by
 
 new client in_ch out_ch
 where 
in_ch is an input channel representing the input direction of the
 TCP stream, and where 
out_ch is an output channel representing the output
 direction of the TCP stream.
class client : Netchannels.in_obj_channel -> Netchannels.out_obj_channel -> object .. end