How do I unsubscribe from this mailing list?

However, this will not work if you are not listed on the main mailing list, but instead receive the mail from a distribution point. In that case, you will have to track down at which distribution point you are listed. Inspecting the "Received:" headers on the mail messages may help, along with liberal use of the "EXPN" or "VRFY" sendmail commands through "telnet smtp". Ask your postmaster for help.