I would like to have a server notes.ini option (perhaps SMTPDFRRetry="File cannot be created") to force the router to intercept DFRs with the specified error message and retry, just like it retries on transient errors. Should be able to specify multiple errors. The problem is that we get these errors for no apparent reason. When resending later, the message goes through, so the problem was not really permanent. It was really transient despite the code in the DFR. If we can override DFR handling at the Domino router, we can have the server retry instead of panicking the end users and generating help desk calls.