The former boss of Camelot, Mr Railton, told sub-postmasters on Wednesday that the Post Office "urgently" needed "a fresh start", with a "new deal" putting them at the "heart of this business".
It has become increasingly reliant on government subsidy and the retail side of its business, reporting pre-tax losses of £81m in 2022-23.
Today, nearly half of its branches are not profitable or only make a small profit from the Post Office element of the business.
It has faced a "tough" time in the last 10 years, Mr Railton acknowledged, which meant that sub-postmasters' remuneration has "lagged behind".
He said that the plans set out would provide more than £250m each year to postmasters by 2030, although this would be subject to government funding.
It also aims to improve branches’ banking offer for customers, and will see a "lower-risk, better value" IT system introduced for sub-postmasters.
On Monday, the European boss of Fujitsu, the company which developed the faulty Horizon system, admitted he "does not know" if the software is currently reliable.
A survey in September revealed almost seven in 10 sub-postmasters have experienced an "unexplained discrepancy" on the Horizon system since January 2020.