A tcp_local_slave.log-* file
A set of channel _master.log-* files for each destination channel
A set of mail.log_current records that show the path of the message
All files should have timestamps and message ID values that match the message ID: header lines in the mail.log_current records. Note that the exception is when messages are bounced back to the sender; these bounced messages will have a different message ID value than the original message.
Examine the tcp_local_slave.log-* file to determine if the message had the message part when it entered the message queue.
Look at the SMTP dialog and data to see what was sent from the client machine.
If the message part did not appear in the tcp_local_slave.log-* file, then the problem occurred before the message entered the MTA. As a result, the message was enqueued without the message part. If this the case, the problem could have occurred on the sender’s remote SMTP server or in the sender’s client machine.
Investigate the copies of the message files to see where the message part was altered or missing.
If any message file showed that the message part was altered or missing, examine the previous channel’s log file. For example, you should look at the conversion_master.log-* file if the message part in the message entering the tcp_intranet channel was altered or missing.
Look at the final destination of the message.
If the message part looks unaltered in the tcp_local_slave.log, the message files (for example: ZZ01K7LXW76T7O9TD0TB.KEEP1), and the channel_master.log-* files, then the MTA did not alter the message and the message part is disappearing at the next step in the path to its final destination.
If the final destination is the ims-ms channel (the Message Store), then you might download the message from the server to a client machine to determine if the message part is being dropped during or after this transfer. If the destination channel is a tcp_* channel, then you need to go to the MTA in the message’s path. Assuming it is an Messaging Server MTA, you will need to repeat the entire troubleshooting process (See 18.104.22.168 Identify the Channels in the Message Path, 22.214.171.124 Manually Start and Stop Channels to Gather Data, and this section). If the other MTA is not under your administration, then the user who reported the problem should contact that particular site.