The inquiry into Australia Post, which opened its first post office more than 200 years ago in 1809, will look at ways to diversify services to ensure they remain commercially viable.
It comes following a referral from Communications Minister Anika Wells, who said shifting consumer behaviour had challenged the sustainability and accessibility of the "beloved institution".
"That's why I've asked the committee to explore how we can better support a sustainable and accessible postal service that delivers for all Australians," she said in a statement.
"Changing consumer behaviour and commercial conditions present significant challenges to the sustainability of our national postal service, reflecting experiences globally."
The inquiry will invite everyday Australians, businesses and stakeholders to provide feedback, with the aim of ensuring the postal service meets evolving community needs.
It comes after it was revealed Australia Post's chief executive Paul Graham received a bonus of more than $1.36 million, despite the company recording a $107.6 million loss in past financial year.
Susan Templeman, chair of the Standing Committee on Communications, Arts and Sport, welcomed the minister's referral as an opportunity to hear from communities on future options for postal services.
The committee is slated to hand down its report in the second quarter of 2027.
Australia Post has tried to balance a rising number of parcel deliveries amid plummeting mail volumes.
Packages and services revenue hit a record $8 billion in the year to June 30, while losses from sending letters fell to $63.2 million.
Letter deliveries have been cut to every second day in a cost-saving measure.
The new delivery model alone saved the company $188.3 million over 12 months.
