README (Revision 1.5) says:
License Evolution:
So now Hypermail is under GNU.
This should probably read "GNU GPL" or even better:
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
as in COPYING (Revision 1.1.1.1) you can find the GNU GPL Version 2.
However in the three source files in archive/ you will find
This license statement forbits commercial use and thus is a proprietory software license incompatible with the GNU GPL. It does not seems to be a derivate work of hypermail, thus the license seems to be possible. However it not being Free Software there are three options:
Note that the functionality is not completely superceded by the new hypermail functions. And then some people are running old version of hypermail which want to keep the structure.
Bernhard
This archive was generated by hypermail 2.3.0 : Sat 13 Mar 2010 03:46:12 AM GMT GMT