I don't know how spammers operate, but they really seem quite
professional at it, since whenever I have added a new RBL
sources to my blacklisting MTA the amount of spam is reduced
only for few days or perhaps weeks. Pretty soon, they are able
to reroute whole damn thing and we are back on the same level
we started from.
And they are doing the very same thing in message headers,
the message itself. They are trying to keep ahead of the spam
prevention and they're really doing pretty good job there.
They get their living out of it.
Do you really think they would not do it for LMAP? Or any
other means? Of course they will. As long as they can.
If there are easy, and relatively cheap ways to circumvent
a problem, then they'll do it.
If spam can be looked at as a disease than RBLs are treating the
symptoms by listing IPs that are likely to abuse the network. LMAP, MTA
MARK and related proposals are more geared towards treating the causes
of the disease by addressing some of the architechtural issues on the
Internet that allow spam to proliferate. For example, spammers are free
to forge the MAIL FROM address with any domain in place. LMAP addresses
this forgery issue forcing spammers to use their own domains. MTA MARK
addresses the issue of hijacked computers being used for sending spam.