He is one of the original designers of the MIME protocol for formatting multimedia Internet electronic mail and sent the first e-mail attachment.

He received the New York University Olive Branch Award for writing about peace in 1990, for an essay about his brief experience as a NATO consultant.

[6] His mentors include his doctoral advisor and the director of the Andrew project, Jim Morris, and Einar Stefferud, who initiated the MIME and First Virtual work.

Borenstein lives with his wife, Trina, in Ann Arbor and Greenbush, Michigan; they have four grown daughters, and five grandchildren.

[8] In 1973, with the help of the ACLU, he became the first US student ever to be awarded money damages from his principal and school board,[9] in Bexley, Ohio, for violating his freedom of speech in 1972, by sending him home for wearing a black armband on the second anniversary of the Kent State shootings.