Sources in the Intelligence Bureau say that the mail was sent out from India itself but bounced off a proxy server in South Africa.
"These are the early leads and the senders are experts on the job," an IB official said
The mail which was sent out claimed responsibility for the blast and also warned that it would even attack the Supreme Court if Parliament attack accused Afzal Guru's mercy plea was not accepted.
IB sources say that 'while the HuJI link is under the scanner, we are still to come to a final conclusion. All angles are open as of now.'
The IB, meanwhile, continues to study the mail. "It appears to have come out of South Africa, but we are certain it was sent out locally. Further it is also being ascertained whether the mail was actually sent out by the HuJI or by mischief makers," they added.
However one thing is sure and that a professional had undertaken this exercise, the IB sources point out.
Another angle that is being probed is whether a radical group from northeast carried out the attack.
"We do not see any immediate motive for any terror group to carry out the attack, but the HuJI angle looks the strongest at the moment, and that is only due to the mail," sources added.
