MailStream Plus How come the Mail.dat files created as variable length files.

The Mail.dat files are created as variable length files because the IDEAlliance Group kept changing the file lengths
with every USPS Postal regulation change. This meant that Pitney Bowes developers would have to change the software to fit the Mail.dat layout change and in turn [users] would have to change their previous JOB setups with every new release. The Pitney Bowes Product Management Manager decided to make the mail.dat file variables and provide a program for the mainframe environment to change the files from variable to fix [see attached]. The mail.dat files created in the window environment are processed as variable files but windows will not write pass the logical data character [meaning the end of the file is represented by the last physical data character and the [#] represents the end of the file in mail.dat.
UPDATED:  September 6, 2017