Intermittent CFMAIL issue

Hello, everyone.

I've got an intermittent CFMAIL issue that has me perplexed.

I'm using CFMAIL to email notifications of changes made to records in a database.  In the form that is used to make these changes there is a field that has email addresses of developers who need to be notified of these changes.  These are a comma-delimited list of email addresses (which, according to CF9 cfmail documentation on adobe.com, is the correct way of sending to more than one address.)

Some of the records will send the email, update the timestamp on the "mailsent.log", append the new email notification to "mailsent.log", and the email is received by the person(s) to whom it was sent.

Other records, however, will (apparently) send the email, will NOT update the timestamp on "mailsent.log", but WILL append a successfully sent entry to "mailsent.log" (even though the timestamp was not updated), and the email is NOT received by the person(s) to whom it was sent.  In these cases, the timestamp of the mailsent.log will not match the timestamp of the latest entry in the mailsent.log.

I've been able to determine one record that will always successfully complete the process, and one record that will always append a success entry (not altering the log timestamp) but the email will never reach its destination.  I am not seeing anything in any of the data that could break the transport of the email (it's all plain text, no special characters.)

Any thoughts on this?

Thank you,

^_^