The Rameswaram (Boat Mail) Express, formerly known as the Boat Mail or Indo-Ceylon Express, is an express train connecting Rameswaram with the state capital Chennai via Tambaram, Chengalpet, Melmaruvattur, Viluppuram, Cuddalore port, Chidambaram, Sirkazhi, Mayiladuthurai, Tanjore, Tiruchchirappalli, Pudukkottai, Karaikudi, Sivagangai, Manamadurai, Paramakkudi and Ramanathapuram.

In the 20th century, it operated as a combined train-steamer ferry-train service between India and Sri Lanka, linking Chennai and Colombo.

It now runs from Chennai Egmore to Rameswaram via Villuppuram, Kumbakonam, Tiruchchirappalli, Pudukkottai, Karaikkudi, Devakottai, Manamadurai, Paramakkudi, Ramanathapuram, Mandapam, and Pamban.

The train's name commemorates the 19th century mail service between Tamil Nadu and Sri Lanka (then Ceylon).

In 1964 a passenger train was washed into the sea by huge waves during the 1964 cyclone, when nearing Dhanushkodi.

[5][6] The train consists of 23 coaches.It shares its rakes with Sethu Superfast Express, operates daily and covers a distance of 667 km (414 mi).

At one time the South Indian Railway considered constructing a bridge 12 miles (19 km) long across the shallow waters and sand shoals and reefs known as Adam's Bridge between India and Sri Lanka.