Mail Abuse Prevention System
From Wikipedia, the free encyclopedia
The Mail Abuse Prevention System (MAPS) is an organisation that provides anti-spam support by maintaining a DNSBL. They provide five black lists, categorising why an address or an IP block is listed:
- Real-time Blackhole List (RBL), the one for which MAPS is probably best known.
- Dialup Users List (DUL), blocks of addresses that include many SOHO users.
- Relay Spam Stopper (RSS), spam relays, e.g. hijacked servers.
- Open Proxy Servers (OPS), naively open SMTP servers.
- Non-confirming Mailing List (NML), marketers who use opt-out strategy.
The acronym MAPS is spam spelled backward.
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[edit] History
MAPS was founded in 1996 as a non-profit organization to pioneer innovative anti-spam techniques (e-mail). The early history of MAPS is the History of DNSBLs itself. Educating users as well as postmasters has always been an attitude of the team.
In 2001 the company started to require a subscription for accessing their lists. Non-subscribed users received a dummy unlisted response. MAPS explained that their expectation to get enough funds from free support failed, forcing them to make that decision. However, the spirit of the company remained that of a non-profit organization. Their subscription page was quite hidden in their .org web site, and their fax-based subscription mechanism was rather awkward.
In 2004 MAPS became a division of Kelkea, Inc. They moved from Redwood City to San Jose, and from .org to .com.
In June of 2005, Trend Micro, Inc. acquired Kelkea. That brought substantial improvement to the subscription mechanism, including a fully automated method for getting temporary subscriptions. In addition, subscribers are provided with personalised web pages where they can view reports and also set up whitelisting and blacklisting options. Whitelisting is particularly convenient, as it allows to whitelist thousands of IP addresses with a few clicks.
[edit] Criticism
Proposing so many lists can confuse a MAPS subscriber; postmasters may hurriedly subscribe to all lists. The difference between an open proxy that relays spam and a, somehow open, spam relay is not clear, and so postmasters may just conclude that the more lists they use the more spam they block. However, one of MAPS lists, the DUL, is significantly different from the others. DUL addresses are dynamically assigned or statically allocated to end-users, they are not directly related to spam and there is no evidence in MAPS archives that any such address has ever been used to relay spam.
DUL's purpose is to educate users to relay mail through an acknowledged ISP, rather than running their own mail servers. That behaviour would bring various advantages. Acknowledged ISPs can, in general, afford to monitor their systems more thoroughly in order to avoid viruses, hijackers and similar threats. Furthermore, it paves the way for effectively exploiting policies like SPF that rely upon end-user SMTP authentication in order to block email address abuse.
However, MAPS fails to disambiguate the concepts of acknowledged ISP versus end-users of IP addresses with a formal definition. In addition, when coupled with the ability to easily whitelist IPs by Local Internet Registry/region, using the DUL to block mail might result in an obscure policy that jeopardises the universal reliability of email delivery.
