Applies to establishments engaged in providing large volume mailing and addressing services. This could be the routine mailing of periodicals or advertising brochures or a one-time letter to a particular list of recipients. Work contemplated by this classification includes, but is not limited to, folding, sorting, labeling and stuffing envelopes (either by hand or machine), clerical support, outside sales work, pick up of preprinted material from a client's location and delivery of completed work to the client or post office when done by employees of an employer having operations subject to this classification. Companies in this classification may also research and compile mailing lists as an additional service for their clients who are involved in direct mail advertising. This classification includes contracting of complete mail room services at a client's location.

This classification excludes printing of advertising material which is to be reported separately in classification 4101 and photocopying or duplicating of printed material, private mail box services (receipt and mailing of routine ready-to-mail letters and packages) for box renters, and package wrapping/mailing services, all of which are to be reported separately in classification 6406.