full-disclosure - A Report on SPAM Blackholes, Blocking/Filte ring, and AOL

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <9B66BBD37D5DD411B8CE00508B69700F033F26C0@pborolocal.rnib.org.uk>
From: John.Airey at rnib.org.uk (John.Airey@...b.org.uk)
Subject: A Report on SPAM Blackholes, Blocking/Filte
	ring, and AOL

Jason, you are spot on. Provided you test that you aren't a relay yourself,
there's little you can do to prevent SPAM. 

Blackholes may refuse legitimate email from sites that aren't set up
correctly. If that site then can't email anyone at all, they are unable to
communicate with the company that blackholed them. Perhaps it would be
better to bombard their postmaster account with warnings about open relay to
give them a chance to communicate and fix it first? 

Some sites may not have reverse DNS entries for their SMTP server. Do you
refuse email from them? I've had this suggested to me before, but that would
prevent legitimate email coming just because someone messed up a reverse DNS
record. I've done it before myself and our own system rejected the outbound
email.

Filtering doesn't work, because the spammers use different techniques.
Anyone seen the latest trick, to use a Mailer-Daemon message of returned
email? It looks like a bounced message when it isn't.

The House of Commons has a filtering system which rejects emails with the
word sex in them (a little indiscriminate). However, they are debating a
Sexual Offences Bill soon, so constituents emails were being dropped about
the subject (Democracy in action? Considering that the bill would legalise
homosexual acts in public toilets but criminalise heterosexual acts almost
anywhere outside a cynic would not be surprised.)

It would be nice to think that our governments can stop SPAM through
legislation, but they really aren't interested. Which in the light of the
preceding is a little surprising.

- 
John Airey, BSc (Jt Hons), CNA, RHCE
Internet systems support officer, ITCSD, Royal National Institute of the
Blind,
Bakewell Road, Peterborough PE2 6XU,
Tel.: +44 (0) 1733 375299 Fax: +44 (0) 1733 370848 John.Airey@...b.org.uk 

A fundamentalist - what you call someone more sure of what they believe than
what you are

- 

NOTICE: The information contained in this email and any attachments is 
confidential and may be legally privileged. If you are not the 
intended recipient you are hereby notified that you must not use, 
disclose, distribute, copy, print or rely on this email's content. If 
you are not the intended recipient, please notify the sender 
immediately and then delete the email and any attachments from your 
system.

RNIB has made strenuous efforts to ensure that emails and any 
attachments generated by its staff are free from viruses. However, it 
cannot accept any responsibility for any viruses which are 
transmitted. We therefore recommend you scan all attachments.

Please note that the statements and views expressed in this email 
and any attachments are those of the author and do not necessarily 
represent those of RNIB.

RNIB Registered Charity Number: 226227

Website: http://www.rnib.org.uk