Roger Baynes was working as a courier at Port Adelaide when he decided there was a need for a free newspaper in the port, similar to those he had seen in Sydney. So in 1951, in partnership with Len Croker he established the first Messenger newspaper.

An earlier free community newspaper, the Progressive Times, was being published by the Largs North Progressive Association and was taken over by Messenger almost immediately. (Messenger, 15 March 1951, p. 1)

In 1954 Croker left to run the Woodville Times, and a fellow courier, Ron Mitchell, came on board in 1959 to run the Messenger's next acquisition, the Standard. Originally operating in a room above a bicycle shop, the business later moved to a former butcher's shop further along Commercial Road. The company continued to acquire older suburban newspapers and turn them into Messenger titles. These included John Carroll's four News-review titles, the Edwardstown District Community Centre newspaper, and the Guardian, previously run by the Smedley brothers at Glenelg.

By 1962 Messenger newspapers were being delivered to 250,000 homes in and around Adelaide. In 1964, to fund the ongoing expansion, nearly half of the company's shares were sold to the Advertiser. By this time there was a free Messenger Press newspaper being delivered to every home in suburban Adelaide.

In the 1970s and 1980s newspapers in the Adelaide Hills, South Coast and Barossa Valley were added, and in 1988 the City messenger was established to cover the Adelaide CBD. Messenger had several printing firsts, most notably, in 1968, being the first newspaper in the southern hemisphere to own a web offset press - just one year after being the first press to use IBM tape electric typesetting. In 1981 the firm purchased a Mitsubishi L600 colour press, enabling Messenger to print coloured magazines including the Advertiser magazine, Football times, South Australian Radio TV extra and Adelaide matters.

In 1983, shortly before his death, Roger Baynes sold the remaining shares to the Advertiser and from 1988 production was moved to the Advertiser. From 1991 all Messenger newspapers were printed by News Limited.