Spamhaus.org shows that MCI/UUNet now hosts 189(!) known spammers, many
of them ROKSO.

You can see in S2955 how the listed IP range from MCI/UUNet was
gradually expanded because MCI/UUNet failed to do anything about their
spam problem:

1, 65.223.192.188/31, ns1.atriks.com / ns2.atriks.org
1, 65.223.192.190, atriks.com
1, 65.223.192.143, tickerbar.net
1, 65.223.192.153, transmitted.org
1, 65.223.192.177, cow1.domaincow.com
1, 65.223.192.178, cow2.domaincow.com
1, 65.223.192.142, virtualmda.com
1, 65.223.192.175, host175.atriks.com
1, 65.223.192.144, ns1.greenhorse.com / ns2.tickerbar.org
1, 65.223.192.128 - 65.223.192.191, atriks.com / "MAX MEDIA MARKETING"
(UUNet)
1, 65.223.192.0 - 65.223.192.255, UUNet (atriks.com / "MAX MEDIA
MARKETING")
1, 65.223.182.0 - 65.223.202.255, UUNet (atriks.com / "MAX MEDIA
MARKETING")
1, 65.223.172.0 - 65.223.212.255, UUNet (atriks.com / "MAX MEDIA
MARKETING")
1, 65.223.162.0 - 65.223.222.255, UUNet (atriks.com / "MAX MEDIA
MARKETING")
1, 65.223.152.0 - 65.223.242.255, UUNet (atriks.com / "MAX MEDIA
MARKETING")
1, 65.223.142.0 - 65.223.252.255, UUNet (atriks.com / "MAX MEDIA
MARKETING")
1, 65.223.132.0 - 65.224.6.255, UUNet (atriks.com / "MAX MEDIA
MARKETING")

As long as MCI/UUNet continues to act irresponsible and allows their
customers to spam us (tinu), this listing will not go away. Au
contraire, it will probably grow to encompass more and more of
MCI/UUNet.

In other words: You rented space in a sewer. Don't complain about the
stench.

You should also read this article:
http://www.spamhaus.org/news.lasso?article=158

You now have the choice between the following 5 possible solutions:
1. Convince your provider to drop all the spammers he hosts. Once there
are no more spammers on this part of the internet, SPEWS is very likely
to delist you. Good luck.
2. Change to a more reputable provider that is not listed in SPEWS or
other blacklists. Post a timetable for the move and SPEWS might even
cut a temporary hole for you.
3. Smart-host outgoing mail. Disadvantage: You'll still pay money to a
spam-supporting company.
4. Ask your recipients to whitelist you. Disadvantage as above.
5. Live with the SPEWS listing. Disadvantage as above.

Good luck,

A. Friend

The usual disclaimer:
I am not SPEWS. We (tinw) are not SPEWS. All comments are just my
private opinion, based on my observations of former actions of SPEWS.
Don't expect SPEWS to answer. SPEWS speaks through actions, not words