envelope stuffer

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun One whose job is to manually insert sheets of printed paper into envelopes for mailing, especially as an example of a person whose work is menial and unfulfilling.
• noun A machine that mechanically insert sheets of printed paper into envelopes.
• noun An advertisement, flyer, or other unsolicited printed material contained in an envelope received by mail.