There are a number of possible causes for this error message:
- A message is not fully received by the MailEnable SMTP service. The last line of the MAI file in the Bad Mail\Messages directory will indicate the error that caused this.
- The post office connector cannot deliver a message to a users inbox. This would happen only in rare cases where a user is deleted just after a message has been accepted by an external connector, but before it has been delivered. It can also occur is the users inbox directory is not a valid path.
- When a delivery delay or failure notification has the recipient and sender the Postmaster address the same. This would indicates that the bad mail sender address configured in the SMTP properties is not a valid email address.
- When the total length of the recipients for an email is too long for the amount of individual email addresses. Basically a check for an invalid recipient string. Might occur if the command file was generated externally to MailEnable (i.e. external program is creating files for MailEnable to send, but has not configured the command file correctly).
- If a command file is found in the SMTP outbound, but there is no message contents file. This can happen if external programs are creating the command file before the message file directly in the SMTP outbound directory (i.e. MailEnable reads the command file to send email, but the message file has not been created yet).
- If a delivery delay/failure notification message has expired in the queue.
- A delivery delay/failure notification message has a permanent error.
- A variety of List Server errors can put messages in Bad Mail.
Please check through each of these to hopefully find the cause in your case.
I hope this answers your question.
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