When using cfmail in ColdFusion to send a large number of emails (usually more than 500) and the emails contain attachments with long filenames, some of the emails do not get sent and are moved to the Undeliverable folder. This is logged as issue 65095.
It appears that ColdFusion inserts a new line character into the email before it leaves the Spool directory and therefore the file becomes corrupted, resulting in the following error message in the mail.log file:
"Error","scheduler-0","10/17/06","15:23:00",,"The ColdFusion mail spool encountered an invalid spool file in the spool directory. The invalid file was Mail31301.cfmail. This file was moved to the undelivered directory."
The ColdFusion MX 7 hot fix JAR file does not need to be retained after installing it with the ColdFusion Administrator. The file has been copied into the correct location.