The mailing list was established in July 2001 using Mailman, the GNU Mailing List Manager. The archives of the list are publicly available. The list resides at the College of Computer Science at Northeastern University in Boston, where the entire BioNLP.org site lives.
Access the mailing list homepage, at https://lists.ccs.neu.edu/bin/listinfo/bionlp There you will find out about the list, including how to join. Though only members can mail to the list, the archives are public.