PQ61018: SMTP COMPATIBILITY FOR 452 RESPONSE CODE TO 'RCPT TO' COMMAND

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• A new interpretation of response code 452 to mean "Too many
  recipients" after a RCPT TO command was added to RFC 2821.
  While the OS/390 SMTP is coded to RFC 821 (and uses code 552 for
  this meaning), other vendors' servers are being deployed which
  use this new code.  The SMTP response to any 4xx code is to
  terminate the current note and queue it for retransmission at a
  later time.  If the partner server is sending 452 for the new
  meaning, this causes the OS/390 SMTP server to keep the note
  at the top of the queue which blocks transmission of any other
  notes for delivery.
  The OS/390 SMTP server needs to allow the customer a choice
  to handle the 452 response for the RCPT cmd using
  the new interpretation for compatibility with other servers
  being deployed on the Internet.
  

Local fix

• Rename the ADDRBLOK and NOTE data sets that the SMTP log
  shows as being repeatedly rejected by the destination server
  with 452 during the RCPT TO commands.
  Modify any local note creation processes to only place 100 or
  fewer RCPT TO commands in an individual copy of a note (100 is
  the minimum that all servers must support).
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of the IBM Communications Server   *
  *                 for OS/390 Release 10 IP and z/OS Version    *
  *                 1 Release 2 IP: SMTP                         *
  ****************************************************************
  * PROBLEM DESCRIPTION: During RCPT command processing when the *
  *                      SMTP client receives a reply code of    *
  *                      452 it stops processing the mail.       *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  In RFC 821, the reply code of 452 during RCPT command is
  interpreted by the SMTP client as 'insufficient system storage'.
  Therefore, the SMTP client stops processing the mail to
  allow the remote SMTP server some time to recover. The mail
  is resent at a later time interval. SMTP client behaves
  differently if it receives a 552 reply code which is
  interpreted as 'too many recipients'. In this case the
  SMTP client can continue to pass the DATA command and the
  mail for the successful recipients received by the SMTP
  server. This scenario is documented in RFC 821.
  
  The remote SMTP server in this case was passing a reply
  code of 452 instead of 552 as documented in the new RFC 2821
  and expected the older implementation to behave correctly.
  +-------------------------------------------------------------+
  + Please check our Communications Server for OS/390 homepages +
  + for common networking tips and fixes.  The URL for these    +
  + homepages can be found in Informational APAR II11334.       +
  +-------------------------------------------------------------+
  

Problem conclusion

• SMTP code has been modified to handle a new configuration
  parameter RCPTREPLY452. The RCPTREPLY452 statement allows the
  customer to specify that the SMTP client interprets the reply
  code of 452 received on the RCPT command as 'too many
  recipients'. Note that the SMTP client will continue to handle
  the 552 reply code as 'too many recipients' also.
  
  The following documentation changes have been made:
  
  ================================================================
  IBM Communications Server
  IP Configuration Guide
  Document Number SC31-8725
  Document Number SC31-8775  (z/OS only)
  
  and
  
  IBM Communications Server
  IP Configuration Reference
  Document Number SC31-8726
  Document Number SC31-8776  (z/OS only)
  
  Chapter "Configuring the SMTP Server", Step 6 Summary of SMTP
  Configuration Statements, add the RCPTREPLY452 statement and
  the description "Enables SMTP to handle reply code 452
  differently for the RCPT command".
  
  Chapter "Summary of SMTP Configuration Statements", add the
  RCPTREPLY452 Statement
  
    Use the RCPTREPLY452 statement to cause the SMTP client
    to interpret the 452 reply code being received on the
    RCPT command as 'too many recipients'. Note that the SMTP
    client will continue to handle the 552 reply code as 'too
    many recipients' also.
  
    If this statement is not present, the SMTP client will
    interpret the 452 reply code as 'insufficient system
    storage' and the mail processing is halted.
  
    Syntax
  
    >>----RCPTREPLY452----------------------------->
  
    Parameters None
  
    Examples
               To change the SMTP client's interpretation
               of the 452 reply code received on a RCPT
               command the following statement is coded:
  
               RCPTREPLY452
  
  
    Usage Note
         None
  
    Related Topics
         None
  
  ================================================================
  
  IBM Communications Server
  IP Messages:
  Volume 1 (EZA)
  Document Number SC31-8517
  Document Number SC31-8783  (z/OS only)
  
    --------------------------------------------------------------
  
    EZA5573I RcptReply452 Active            : <state>
  
    Explanation: Indicates whether the RCPTREPLY452 statement
    was present in the hlq.SMTP.CONFIG file.
  
    <state> is one of the following:
  
    YES - The RCPTREPLY452 statement was present. The SMTP client
          interprets the 452 reply code received during RCPT
          command processing to mean 'too many recipients'.
  
    NO  - The RCPTREPLY452 statement was not present. The SMTP
          client interprets the 452 reply code received during
          command processing to mean 'insufficient system storage'
          and the mail processing is halted.
  
    See IBM Communications Server: IP Configuration Reference
    for more information about the RCPTREPLY452 configuration
    statement.
  
    System Action: SMTP continues.
  
    User or Operator Response: None.
  
    System Programmer Response: None.
  
    Source Data Set: SMTP
  
    Procedure Name: OpenOutputStreams
  
  
  * Cross Reference between External and Internal Names
  EZAAA00H (MSSMTP  )  EZABB01X (SMTP    )  EZABB028 (SMTPRPLY)
  EZAEB01B (SMTPCONF)  EZAAA00H (MSSMTP  )  EZABB01X (SMTP    )
  EZABB028 (SMTPRPLY)  EZAEB01B (SMTPCONF)
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UQ66762 UQ66763 PQ03275

Modules/Macros

• EZAAA00H EZABB01X EZABB028 EZAEB01B
  

Fix information

• Fixed component name

  TCP/IP V3 MVS

• Fixed component ID

  5655HAL00

Applicable component levels

• R120 PSY UQ66762

     UP02/06/17 P F206

• R50A PSY UQ66763

     UP02/06/17 P F206

Fix is available

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