Spam blocking and false positives
Would anyone be interested in sharing what anti-spam solution you're using and what the rate of false positives is?
Re: Spam blocking and false positives
GFI Mail Essentials 14.1 utilizing the directory harvesting protection feature. After some considerable tweaking we have had no false positives in 4 months. About 10,000 emails per day. Cheers. On Tue, Dec 15, 2009 at 11:56 AM, Steve Hart wrote: > Would anyone be interested in sharing what anti-spam solution you're > using and what the rate of false positives is? > > >
Re: Spam blocking and false positives
VIPRE with RBL blocking using spamhaus will give you 0 false positives. But you'll need to tweak the settings a bit to increase the catch levels, but once done it's pretty much set and forget with rare FP's. Roger Wright ___ On Tue, Dec 15, 2009 at 12:56 PM, Steve Hart wrote: > Would anyone be interested in sharing what anti-spam solution you're > using and what the rate of false positives is? > > >
RE: Spam blocking and false positives
Vipre from Sunbelt Software, and <1%. Sean Rector, MCSE From: Steve Hart [mailto:sh...@wrightbg.com] Sent: Tuesday, December 15, 2009 12:57 PM To: MS-Exchange Admin Issues Subject: Spam blocking and false positives Would anyone be interested in sharing what anti-spam solution you're using and what the rate of false positives is? Virginia Opera's 35th Anniversary Season The One You Love Celebrate with a 2009-2010 subscription: La Boh?me?|?The Daughter of the Regiment?|?Don Giovanni?|?Porgy and BessSM Visit us online at www.VaOpera.org or call 1-866-OPERA-VA The vision of Virginia Opera is to enrich lives through the powerful integration of music, voice and human drama. This e-mail and any attached files are confidential and intended solely for the intended recipient(s). Unless otherwise specified, persons unnamed as recipients may not read, distribute, copy or alter this e-mail. Any views or opinions expressed in this e-mail belong to the author and may not necessarily represent those of Virginia Opera. Although precautions have been taken to ensure no viruses are present, Virginia Opera cannot accept responsibility for any loss or damage that may arise from the use of this e-mail or attachments.
Re: Spam blocking and false positives
On Tue, Dec 15, 2009 at 09:56, Steve Hart wrote: > Would anyone be interested in sharing what anti-spam solution you're using > and what the rate of false positives is? I have put up Maia Mailguard here. Personal Stats: Efficiency 98.94% False Positive 0.10% False Negative 0.96% Sensitivity 96.79% PPV 99.67% Specificity 99.86% NPV 98.64% Site-wide Stats: Efficiency 92.38% False Positive 0.05% False Negative 7.57% Sensitivity 90.50% PPV 99.92% Specificity 99.73% NPV 72.81% Of course, the site-wide FP stats (and others) are dependent on the users rescoring the emails. Mine are accurate, as I'm a real hawk on training and classifying - the others, well, not so much... Kurt
RE: Spam blocking and false positives
We use SpamTitan - we get about 4,000 messages a day. About 800 are clean, the rest are blocked. I can't remember the last time we had a false positive, and we get few false negatives - I personally had maybe 3 or 4 false negatives in the past year. Ralph From: Steve Hart [mailto:sh...@wrightbg.com] Sent: Tuesday, December 15, 2009 12:57 PM To: MS-Exchange Admin Issues Subject: Spam blocking and false positives Would anyone be interested in sharing what anti-spam solution you're using and what the rate of false positives is? Confidentiality Notice: -- This communication, including any attachments, may contain confidential information and is intended only for the individual or entity to whom it is addressed. Any review, dissemination, or copying of this communication by anyone other than the intended recipient is strictly prohibited. If you are not the intended recipient, please contact the sender by reply email, delete and destroy all copies of the original message.
RE: Spam blocking and false positives
> Would anyone be interested in sharing what anti-spam solution you're > using and what the rate of false positives is? The answer to the second question will vary significantly, even when the answer to the first question is the same; it depends greatly on the specific local configuration and who/what is sending the incoming mail to the site. In fact, this will vary enough that I wouldn't even assign a weight metric to base a purchasing decision on the answers here. Realizing that, we use Ironport here. I myself have received one spam message in 3 years since its implementation. FP have ranged from "an I.T. administrative burden" when we blocked for non-matching reverse DNS, to what is now almost immeasurably miniscule in our current configuration (we block on lack of reverse DNS). We block on Spamhaus Zen and are pretty aggressive with what we block via senderbase. We are also aggressive with SMTP protocol compliance settings. The mix of sites sending to us include large federal and state agencies, the usual large freemail providers, mailing lists such as this, and small to medium consulting and professional services firms. Slight rant follows... It is that latter category of senders who represent 99+% of the false positives we experience. This is due to, typically, an egregiously poor messaging/dns infrastructure in place at these small firms, set up by someone's brother who "knows about that thar internet thing." These type of places will also typically not control their AV, do not have patch management, and do not block outbound port 25 from their LAN. Because of this, they do end up on RBLs from time to time and so I guess that could be considered a FP by some when they are blocked. This happens 2-3 times per year for us now. When they are shown the evidence they will usually jump into action, so there is at least a small ray of sunshine in this story. ~JasonG
Re: Spam blocking and false positives
Cisco IronPort. Nil on the false positives so far, and we've had it a couple of months. The content filters pull some false positives, for obvious reasons, but they are easy enough to tune. 2009/12/15 Steve Hart > Would anyone be interested in sharing what anti-spam solution you're > using and what the rate of false positives is? > > > -- "On two occasions...I have been asked, 'Pray, Mr Babbage, if you put into the machine wrong figures, will the right answers come out?' I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question."