For almost a year we've been getting bounced mail from lehman

Hi Webteam,

I'm writing to you because in our mailing list, [email protected], we've=
 been getting bounced mail messages from the mail servers at barkleyscapita=
l.com because it does not recognize the user [email protected].=
  Barkley presumably took over the server from defunct Lehman Brothers and =
that employee no longer works there.  Unfortunately, there appears to be no=
 moderator to get rid of this user - I've sent mail to nbusers-owner@netbea=
ns.org as well as [email protected], but have not gotten any reply.  I=
'm hoping that this mail will find someone with access to the mailing lists=
.

Could someone please get rid of this user?  It's annoying to see these boun=
ced emails for almost a year.  I could easily block them by setting a filte=
r on my mail client, but I feel that just hides the problem.

Any help would be much appreciated.
Thomas Wolf
[email protected]