[Top] [All Lists]

Re: port number for smtp over ssl

2003-01-15 11:02:23

On Wed, Jan 15, 2003 at 09:14:18AM -0800, Dave Crocker wrote:

The 'alternate' port used for doing SMTP over SSL is 465. This appears
to be a well-established, de facto standard.

  Well, yes and no..  It used to be established before  STARTTLS
  command was specified, and like with  IMAPS-port is being superceded
  with IMAP protocol's  STARTTLS extension, same fits also SMTP.

  I don't remember the source, but I have written into  ZMailer's smtp
  server subsystem configuration manual:

       PARAM listen-ssmtp
              Listen  on  port  TCP/465,  which   is   deprecated
              SSL/SMTP listener port.

       PARAM outlook-tls-bug
              Microsoft  does  it again...  If TLS is set at Out-
              look, and server port is not  25,  it  bloody  well
              seems to expect that the server starts in TLS hand-
              shake mode.

              This implements a 2 second startup  delay  in  case
              the port is some other than 25, and if some byte is
              received from client during that time, and it  hap-
              pens to be 0x80, then this server will initiate TLS
              negotiation.   If  nothing  happens  (well-behaving
              client), normal SMTP greeting is presented.

 Dave Crocker <mailto:dhc(_at_)dcrocker(_dot_)net>
 Tribalwise <>

/Matti Aarnio   <mea(_at_)nic(_dot_)funet(_dot_)fi>