Very often with email printers, one or more of the email addresses specified is invalid which then causes the file to be put on hold and the printer edrained. This is by product design. This can cause files to start backing up and never print.
You can change the printer node from ACQUIRE=WORK to ACQUIRE=TIME. This will allow an auto start for these printers when the timer pops for the value specified on global statement ACQTIME. Since the problem file is on hold the rest of the files can begin to print.
Other Relevant Information
See Customization Guide, Chapter 4 under Initialization Parameters for description of statement ACQTIME and Node parameter ACQUIRE.