Messages bouncing between servers or channels are said to be looping. Typically, a message loop occurs because each server or channel thinks the other is responsible for delivery of the message. Looping messages usually have a great many *Received: header lines. The Received: header lines will illustrate the exact path of the message loop. Look carefully at the host names and any recipient address information (for example, for recipientclauses or (ORCPT recipient)comments) appearing in such header lines. One cause of such message loops is user error.
For example, an end user may set an option to forward messages on two separate mail hosts to one another. On his sesta.com account, the end-user enables mail forwarding to his varrius.com account. And, forgetting that he has enabled this setting, he sets mail forwarding on his varrius.com account to his sesta.com account.
A loop can also occur with a faulty MTA configuration. For example, MTA Host X thinks that messages for mail.sesta.com go to Host Y. However, Host Y thinks that Host X should handle messages for mail.sesta.com; as a result, Host Y returns the mail to Host X.
In these cases, the message is ignored by the MTA and no further delivery is attempted. When such a problem occurs, look at the header lines in the message to determine which server or channel is bouncing the message. Fix the entry as needed.
Another common cause of message loops is the MTA receiving a message that was addressed to the MTA host using a network name that the MTA does not recognize (has not been configured to recognize) as one of its own names. The solution is to add the additional name to the list of names that your MTA recognizes as its own. Note that the MTA's thresh holds for determining that a message is looping are configurable; see the MAX_*RECEIVED_LINES option.dat options (Option File Format and Available Options in Sun Java System Messaging Server 6.3 Administration Reference). Also note that the MTA may optionally be configured--see the HELD_SNDOPR global MTA option--to generate a syslog notice whenever a message is forced into .HELD state due to exceeding such a thresh hold. If syslog messages of Received count exceeded; message held.are present, then you know that this is occurring.
You can resend the .HELD message by running release in Sun Java System Messaging Server 6.3 Administration Reference or following these steps:
Rename the .HELD extension to any 2 digit number other than 00. For example, .HELD to .06.
Before renaming the .HELD file, be sure that the message has stopped looping.
Run imsimta cache -sync. Running this command will update the cache.
Run imsimta submit channel or imsimta run channel.
It may be necessary to perform these steps multiple times, since the message may again be marked as .HELD, because the Received: header lines accumulate. If the problem still exists, the *.HELD file will be recreated under the same channel with as before. If the problem has been addressed, the messages will be dequeued and delivered.
If you determine that the messages can simply be deleted with no attempt to deliver them, see clean in Sun Java System Messaging Server 6.3 Administration Reference in the Sun Java System Messaging Server 6.3 Administration Reference.