Cyber Crime Cell police, acting on complaints, traced the origin of the objectionable messages to a colony in Ukkadam area in the city and arrested him.
On being questioned, the man told the police he did not know about the origin of the SMS and had forwarded it to 100 persons after receiving it.
Meanwhile, city police commissioner AK Vishwanathan held a meeting with 250 people of the north-east, including students, labourers and businessmen and assured them of safety at their workplace and homes.
He said a helpline has been opened to enable them contact police in case of any emergency. Rumors through e-mail and SMS on attacks on people from north-eastern residing in Tamil Nadu and Karnataka triggered an exodus from these two states in the past four days, which however abated on Sunday.