FAQ: Why does RPM automatically suspend a queue?

Problem: Why is RPM Remote Print Manager™ is automatically suspending my queue?

Answer: When RPM is licensed properly, it should not suspend the queue, unless the Windows print spooler is completely full, or the RPM limit is reached. In the RPM\Options\Settings, set the option to "Ignore settings, always spool jobs". Be careful, this can fill your Windows spooler. Or you can specify a number for RPM to quit submitting jobs.

Please note: this article dates from Windows 3.1 where the Windows spool manager had a maximum number of jobs it could queue at a time.