You have my deepest sympathies. I've been trying for over a year via messages
to postmaster@merit.edu and others, to get rs@tiny.sprintlink.net taken off
the nanog list (I left Sprint last July). I get mail as rs@digex.net
directly, and I get mail forwarded to me via Sprint, which means that I get
two copies of everything that comes along.
Problem is, the folks at Merit consistently deny that rs@tiny.sprintlink.net
is on the list, though if you telnet to merit.edu's smtp port and EXPN the
list, you see rs@tiny.sprintlink.net there, plain as day.
Well, you used to be able to. Now if you telnet to merit.edu port 25 and say
"expn nanog", the expn will eventually time out.
This situation wouldn't be so bad if I could have an ongoing dialog with the
Merit folks until we got things straightened out, but the standard MO seems to
be to ignore the mail for three weeks to a month before sending back a claim
that I'm not on the list and never have been. Then when I respond to that
message, it goes in the bit bucket. I went through three iterations of this,
and then gave up and wrote an incoming mail action to simply delete all
duplicate messages in my nanog mailbox. It's simpler.
Since all other mailing lists I used to subscribe to have propagated to
rs@digex.net and NANOG mail is the only mail to me that routinely traverses
Sprint, it crossed my mind to ask Sprint to point all mail for rs@tiny to
nanog@merit.edu, but that seemed a little mean-spirited. 
---Rob