Preventing small bundles when presorting USPS Marketing Mail Flats into EMM letter trays using MailStream Plus

Product Affected:  MailStream Plus™, all versions, all platforms


  • A mailing was presorting with USPS Marketing Mail Flats into EMM trays.  
  • The pieces were .54 inches thick.  EMM trays are 21.75 inches long, so 40 pieces maximum would fit into a tray (40*.54=21.6 inches)
  • The presort was making some small bundles, for example making 4 bundles in a tray with counts of 13, 13, 13, 1 pieces.
  • The USPS and the mailer did not want the 1-piece bundles.


The cause was that MailStream Plus™ (MSP) was filling the trays to the maximum, even if it meant adding just 1 more piece in a separate bundle.  This was due to the BG FRC (Container force thickness) parameter, which by default has an internal value of 99.99%, so it would always make the trays as full as possible.


UPDATED: March 28, 2019
The solution was to add a BG FRC parameter and in positions 46-50 (Percent of BG MAX Thickness) put 00001 (1%).
BG FRC E                                     00001

This let MSP consider the tray full when all of the normal bundles that were made were in it.  MSP would no longer make or add very small bundles..

This was found in MSP version 8.3.3.  In MSP 8.3.5, the code was changed so that the BG FRC will automatically be set to 1% when putting USPS Marketing Mail flats in letter trays.

In the mailing it was also found that another parameter needed to be added-
ALG BL E E         Y Y

to eliminate a few small bundles that were being made for other reasons.

Some DMM (Domestic Mail Manual) references pertaining to putting USPS Marketing Mail Flats into trays.
(References as-of August 2017).

200 Commercial Letters, Flats, and ParcelsDesignStandards
203 Basic Postage Statement, Documentation, and Preparation Standards
    5.0 Letter and Flat Trays
    5.8 Preparation for USPS Marketing Mail Flats in Letter Trays
    (this section lists some of the requirements)

240 Commercial Mail USPS Marketing Mail
245 Mail Preparation
    3.0 Letter Trays and Sacks
    Letter mailings must be prepared in letter trays with sleeves. Flat mailings must be prepared in sacks except when permitted to be prepared in letter trays under other applicable standards in this section.

240 Commercial Mail USPS Marketing Mail
245 Mail Preparation
    10.0 Preparing Automation Flats
    10.4.2 Required Sacking
    A sack, or a letter tray under 3.0, must be prepared when the quantity of mail for a required presort destination reaches either 125 pieces or 15 pounds of pieces, whichever occurs first, subject to these conditions...