Will MailStream Plus 8.3.3 allow the HEADERP to get the previous rates for mailings going to the USPS before Jan. 22, 2017?

Product Feature: General

Operating System: All Platforms

Database: Not stated

Configuration: Not stated
No, the MailStream Plus 8.3.3 release contains January 2017 regulatory updates, pricing changes, and mailing preparation changes. You must only use Release 8.3.3 for mailings submitted to the USPS® after January 22, 2017. 
Using the HEADER parameter with a P for previous rates in position 7 is not recommended for this version due to complex presort changes.
UPDATED:  March 29, 2017