Security Basics mailing list archives
RE: SPAM filter...
From: "Naren - Pactech" <naren () pactech net>
Date: Tue, 16 Dec 2003 18:04:10 +0800
Agreed with you .. but .. as implemented by one of my own ISP (where I have an account .. ) SPAM Assasin has the highest false positive rates .. As that is beyond my control (i.e. the spam assasin is maintained by the ISP) - there is nothing much I could do. Almost 10 % of my valid emails become tagged as {SPAM} .. In comparison, I would prefer something with a lower false positive rate .. where the ones that missed out can be manually filtered, rather than tagging valid emails .. as SPAM. BTW, I have no experience with Amavisd-New Anyway, I think the issue for Sekhar is on stopping people from finding out valid emails. AS far as I know, there is no hard and fast solution for that: the mail has to reach the database - or end email server, to confirm if the email address that the mail is destined for exists or not ! The solutions for this would be .. 1) dont bounce back unknown email addresses .. (easier to manage if the number of users are small .. ) and instead re-route them to a dummy email address or send to delete 2) filter (on the firewall or gateway .. depending on what you are using) the sources sending these mails .. Dunno if these will solve the problem, or assist you, but I guess, they should help .. !! Naren T. Naren Technical Manager - Pactech Pte Ltd., Singapore Infocomm Security Solutions Distribution and Services o: +65-62711123 p: +65-95778725 e: naren () pactech net w: <http://www.pactech.net> [Firewalls: Borderware - Watchguard - Sonicwall] -----Original Message----- From: Shawn Jackson [mailto:sjackson () horizonusa com] Sent: Tuesday, December 16, 2003 9:19 AM To: Vedantam sekhar; security-basics () securityfocus com Subject: RE: SPAM filter... We use Postfix, Amavisd-New and Spam Assassin and its cut out-of-the-box we filtered 98% of our spam. All of which are open-source projects. Shawn Jackson Systems Administrator Horizon USA 1190 Trademark Dr #107 Reno NV 89521 www.horizonusa.com Email: sjackson () horizonusa com Phone: (775) 858-2338 (800) 325-1199 x338 -----Original Message----- From: Vedantam sekhar [mailto:sekhar56us () yahoo com] Sent: Friday, December 12, 2003 10:05 PM To: security-basics () securityfocus com Subject: SPAM filter... Dear All, Can any body suggest me the mail filter software(Opensource :-)) which can avoid the dictionary atttacks on the server.Our mx server has Solaris O.S. The spammmers are trying to find out the Valid E-mails by blindly sending mails to randomly selected characters as receipent ID? Thanks V.N.SEKHAR This mail has been scanned for known virusses, and spam, using the Borderware MXTreme Mail Firewall. For info, visit http://www.mxtreme.com
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Current thread:
- SPAM filter... Vedantam sekhar (Dec 15)
- RE: SPAM filter... Aditya [ Aditya Lalit Deshmukh ] (Dec 16)
- Re: SPAM filter... Paul Kurczaba (Dec 18)
- RE: SPAM filter... sietze (Dec 22)
- Re: SPAM filter... Nabil SEFRIOUI (Dec 22)
- RE: SPAM filter... Wayne S. Ackley (Dec 23)
- RE: SPAM filter... sietze (Dec 22)
- <Possible follow-ups>
- RE: SPAM filter... Shawn Jackson (Dec 16)
- RE: SPAM filter... Naren - Pactech (Dec 16)
- RE: SPAM filter... Shawn Jackson (Dec 16)
- Re: SPAM filter... Kareem Mahgoub (Dec 16)
- RE: SPAM filter... Shawn Jackson (Dec 16)
- RE: SPAM filter... Chris Santerre (Dec 16)
- Re: SPAM filter... Kareem Mahgoub (Dec 17)
- RE: SPAM filter... Shawn Jackson (Dec 17)
- RE: SPAM filter... Chris Santerre (Dec 17)