On Monday, March 3, 2003, 1:49:02 PM, R. Scott Perry wrote:
RSP> It seems that the problem is occurring when either the remote mailserver
RSP> returns a 421 response (which indicates that IMail should try that server 
RSP> again), or where the remote mailserver responds to the TCP/IP connection by 
RSP> immediately disconnecting (as it would if there was no SMTP server 
RSP> listening on port 25).  In the first case, IMail is acting correctly.  In 
RSP> the second case, it is unclear how the mailserver should respond (the MX 
RSP> record points to a computer that is reachable, but doesn't have SMTP 
RSP> running on it -- most likely, the server is in the process of 
RSP> rebooting).  If anyone knows of an RFC that specifies how this situation 
RSP> should be handled, I would be very interested.

RFC  2821 (Simple Mail Transfer Protocol) section 3.9 (Terminating Sessions
and Connections) has a paragraph that reads:
   SMTP clients that experience a connection close, reset, or other
   communications failure due to circumstances not under their control
   (in violation of the intent of this specification but sometimes
   unavoidable) SHOULD, to maintain the robustness of the mail system,
   treat the mail transaction as if a 451 response had been received and
   act accordingly.

>From  that  point  of  view  it  appears that retrying later is the correct
response.  However, section in 3.1 (Session Initiation) it states that
   An SMTP session is initiated when a client opens a connection to a
   server and the server responds with an opening message.

So  one  could  argue  that an immediate disconnection before receiving the
opening message is the same as not connecting.

-- 
[EMAIL PROTECTED]     "The avalanche has already started, it is too
Rod Dorman              late for the pebbles to vote." � Ambassador Kosh


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