Email notifications may not work with CUPS printer classes in RHEL

Issue

• On our workstations our users sometimes print with lpr -m. The "-m" option is supposed to ensure that they receive an e-mail when the print job is done. I have tried this on Red Hat Enterprise Linux (RHEL) 5.11, 6.6, and 7.1 workstations. While the print job comes through just fine no e-mail is sent out.
• Running lpr -m <print-queue> <file> where <print-queue> is a printer class may not generate an email notification when the print job is complete.