USPS conspiracy to lower rural carrier salaries

[snopes]

Comment: Every year the postal service does a "mail count" to determine
the average amount of mail a rural carrier delivers on a route. The
amount of mail during this period determines the salary for that route for
the rest of the year. It is rumored the the USPS management stores, hides
and tells major mailers not to send mail during the count period. The
management also releases news stories telling citizens not to send mail
from there own mailboxes, because the mail may be stolen. The management
does these things to lower the count scores, so that rural carriers get
paid less for doing more work. Is there any way you can check out this
rumor? Every rural carrier I have ever talked to has heard of this, and I
don't know if I should believe it or not.