Sudhir Mishra’s Calcutta Mail narrates the story of a man (Anil Kapoor) who leaves his hometown and comes to Calcutta searching for something special. He, however, realizes that somebody is watching him and he doesn't know whom to trust. In comes Rima (Rani Mukherjee), but her identity is suspicious. Is she Rima or Bulbul, nothing about her conveys the truth.

He then comes across a number of characters. One among them is Sujan Singh, a joker (Satish Kaushik), a devoted loving father but also a shrewd politician. Can he be trusted?

And there's Ghatak (Saurabh Shukla) always willing to lend a helping hand to everyone friend and foe. Is he to be trusted? Inspector Rastogi played by Sayaji Shinde, a loyal worker who turns away from duty only once to do the biggest favor to the nation.