PN89968: SMTP CREATES LOOPMAIL EVEN THOUGH THERE ARE LESS THAN 25 RECEIVED: LINES

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• SMTP detects that a note is LOOPMAIL even though the number of
  RECEIVED: lines are less than 25.  This customer's scenerio
  involves a distribution list that is first sent to a mailer on
  another system.  This mailer then expands the list to
  individual recipients.  Some or all of these recipients can be
  users on the originating host.  So the note can be sent back to
  the original MVS SMTP host.  SMTP then intermittently detects
  that these notes are loop mail.  The loop mail is not recipient
  dependent. One recipient can receive the note successfully one
  time but the next time, the note will be detected as loop mail.
  .
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All MVS TCP/IP Users using SMTP.             *
  ****************************************************************
  * PROBLEM DESCRIPTION: SMTP erroneously identifies mail as     *
  *                      "loopmail".                             *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  When SMTP processes mail headers, it uses a global variable
  to count the number of "received:" lines. This count is used
  to identify mail that may be looping. It assumes that a piece of
  mail will be completely processed before the next piece of mail
  is examined. In actuality, multiple pieces of mail are being
  processed simultaneously. This causes the value of the global
  variable not to correspond to the actual count of "received:"
  lines in a given piece of mail.
  

Problem conclusion

• To correct the invalid loopmail problem the ReceivedCount
  variable was added to the connection record. This will
  ensure that each connection will have its own ReceivedCount
  variable. Therefore if the mailer is processing multiple
  connections the ReceivedCount will not be corrupted by other
  connections.
  

Temporary fix

Comments

APAR Information

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

  PN87823

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

  UN96788

Modules/Macros

• EZAAI00V EZABB01X EZABB01Y EZABB01Z EZABB02A
  EZABB02B EZABB02C EZABB02D EZABB02E EZABB02F EZABB020 EZABB021
  EZABB022 EZABB023 EZABB024 EZABB025 EZABB026 EZABB027 EZABB028
  EZABB04L
  

Fix information

• Fixed component name

  TCP/IP V3 MVS

• Fixed component ID

  5655HAL00

Applicable component levels

• R320 PSY UN96788

     UP96/10/31 P F610

Fix is available

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