When Can I File for TN Visa Status by Mail?

Question: I am a Canadian citizen currently in N.J. I found an employer who is willing to petition me for TN Visa Status to work in the IT field. Can he apply for TN visa status by mail instead of me going to the border? 

Reply: Canadian citizens, as of October 2012, now have two options to obtain TN visa status. Prior to October 2012, Canadians who were outside of the U.S. could only obtain their initial TN visa status by applying at a U.S. port-of-entry. As result of the rule changes in October, Canadian citizens may now apply for initial TN visa status outside of the U.S. by mailing Form I-129 to USCIS

If an individual is already in the U.S., TN visa status can be obtained by mail using Form I-129 and requesting a change of status. This procedure automatically changes an individual's immigration status from his/her current status to the sought after status without a need for departing and re-entering the U.S. To take advantage of the change of status procedure, an individual needs to document his/her lawful immigration status in the U.S. This can be difficult for Canadian citizens who may have entered as a visitor, and whom most likely did not receive from the border inspector an I-94 card evidencing their lawful visitor status. Sometimes lawful status can be documented by presented a passport admission stamp or other evidence.