The e-mail was sent to Kalam's Web site on Thursday evening and police were trying to trace its origin, the Press Trust of India news agency reported.
Details of the e-mail and police comment on it were not immediately available.
There have been a spate of bomb threats and hoaxes since the Bombay train bombings of July 11 that killed 207 people and wounded more than 800, according to the AP.
The Americans came to realise that they would have to either leave the region or weaken their presence there. It is Russia that is filling the vacuum now