  Controlling TCP/IP SMTP Debugging? 
 The Question is:
 
Alpha 1000A VMS 7.1/UCX 4.2
 
Dear Dr. Wizard, sir:
 
With respect to SMTP, we'd like to capture
whatever information can be had about the
mail delivery session (the mail receiver logs,
for example, showing the actual domain name
and/or IP address of the host that passed the
mail) to assist with tracking spammers, etc.
(since the headers in the mail message are
often forged or insufficient).
 
The UCX$SMTP_LOG_LEVEL logical name
is described in the UCX Management manual,
but only in a general way, and using it does
not appear to provide the needed information.
 
UCX$SMTP_RECV_TRACE and
UCX$SMTP_RECV_DEBUG and
UCX$SMTP_SYMB_TRACE are not described.
 
Please describe each of these logical names,
the values that can be assigned to each,
and the resulting information that is written
to various log files.
 
Thank you.
 
 The Answer is:
 
  UCX$SMTP_RECV_DEBUG is a Boolean, and applies to the reception of
  SMTP messages.  This logical name tells the receiver to log full
  diagnostics.  It performs a similar function to the symbiont's
  UCX$SMTP_LOG_LEVEL 5.
 
  UCX$SMTP_SYMB_TRACE is a Boolean, and applies to the SMTP symbiont.
  This logical name tells the symbiont to log all messages received
  from and transmitted to remote SMTP servers. It allows you to trace
  the SMTP application layer protocol.  Any unprintable and/or control
  characters sent/received are printed as \n where 'n' is the hex value
  of the character. For example, command lines and replies are terminated
  with a &lt;CR&gt;&lt;LF&gt; which would appear in the log like this:
 
    send buf=MAIL FROM:&lt;jones@acme.com&gt;\d\a
    recv buf=250 &lt;jones@acme.com&gt;... Sender OK\d\a
 
  The "\d\a" is the &lt;CR&gt;&lt;LF&gt;. CR is hex 'd' and LF is hex 'a'.
 
  UCX$SMTP_RECV_TRACE is a Boolean, and applies to the reception of
  SMTP messages.  This logical name tells the receiver to log all
  messages received from and transmitted to remote SMTP clients.
  Unprintable characters are handled similarly to UCX$SMTP_SYMB_TRACE.
 
