A clothes dryer vent that is working correctly moves the lint through the dryer vent system to the outside of your house. A build-up of excess lint behind your clothes dryer can be the outcome of a stopped up clothes dryer vent. Considering that a clogged up vent restricts air flow so that the air can not move the lint to the beyond your home, it requires the lint into the area behind your dryer.

Dryer Vent Wizard of Westchester Warns Of Lint Buildup in Areas Behind the Dryer