emails with No Message Collected

[kfliong]

Hi,

I have this problem where some of the outgoing mails are received as <<< No
Message Collected >>>.

All the contents including attachments are ripped and only left with this
message "<<< No Message Collected >>>".

I am not sure if this is related to Mailscanner or any of the settings in
it that i have implemented. This truly strange. So far, I can't find any
pattern that can lead me to diagnose this problem. The sender, recipient,
subject, contents are random.

I would appreciate any help or suggestions. Thanks in advance.