Deputy Inspector General of Police Ashuthosh Pandey has ordered the cyber cell to investigate the case on priority.
According to the girl's family, she got an email two days ago with her photograph crossed out in black and with a warning that she would die June 12.
The desperate girl met senior police officials late Tuesday.
The family told IANS that the threat assumes seriousness as the girl's father was murdered on the same date last year.
The killers are yet to be caught. The family fears the mail may have come from the same killer or killers.
The girl resides on Kabeer Road at Hussainganj. Her cousin brother, who lives near Sikanderbagh, has also received a similar threatening mail.