Thanks Terry,
Consider BIGISP.com, they have 1 mail server mail.bigisp.com
Little company abc.com buys a DSL account from bigisp.com [.....]
Little company spammer.com buys a DSL account from bigisp.com. [.... ]
Now he sends a spam, faking the from address as whatever(_at_)abc(_dot_)com
targeting
victim(_at_)spamtarget(_dot_)com
This will be real problem during next several years until BigISPs will start to
use SMTP AUTH.
I see this is as big problem. There is no reasons for ISPs to support STMP AUTH.
They usualy do not care about spam. Spam is source of thier money.
If end-user will spend more time to recieve his email using dialup - this mean
more money for ISP.
If end-user have to buy 10Mb or 20Mb mailbox instead of current 5Mb - this
mean more money for ISP.
If end-user do not wish to recieve viruses or spam - he can buy additional
services - spam filtering - this mean more money
for ISP.
No real reasons for ISPs to stop spam.
SPF is Server-to-Server auth protocol. It has a lot of disavantaged like one
you have mentioned.
I see only one benefit from current SPF - it does not requere big changes to
send email.
Publish SPF record and you can send.
But in return it does not save you from new kinds of forgery. Additional steps
requered to prevent this.
This is one of biggest problems - make changes in your DNS, MUA, MTA to make it
possible to send any email currently,
or postpone everything until better times (but still requered to make changes).
If SPF will be accepted as standart and DK(or any other cryptography based or
other non-server-to-server tech) I see this:
2004-2005 SPF records published by domain owners
2005-2006 Recievers finaly start to check SPF records. Even more SPF record
published to prevent "unknown" status
Bulk mailing prices increase. Black-hat hackers and script kiddies become
interested in spam money.
2006-2007 New kind of forgery like one you have described deliver spam to you
mailbox
2007-2008 SMTP AUTH and better fine-tuned SPF tech used. But "unknown kind
attack by unknown hackers" claims (Like one I've
described several days ago) started to prevent blacklisting
WeSendSpamSometimes.com domain.
2007-2008 DK or any other technology (which does not requere mail routing
restrictions) started prosecute claims above and
becouse of IPv6 dynamic mail/IP routing nature and unhappy travelers who forces
to use corporate mail servers.
This is my first accuption. Timing can be changed. Other factors like IPv6
acceptance or start of WW3 can delay this.
--
Andriy G. Tereshchenko
TAG Software
Odessa, Ukraine
http://www.24.odessa.ua