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Aug 21, 2006
Blog Post

Are You Losing Important Customer Emails to Your Filters?

SUMMARY: No summary available.
By Anne Holland, President

For the longest time we didn't filter junk mail at all for our incoming email. My concern was that some reader emails would get lost in the filters by mistake, and I had a zero tolerance policy for that.

But then my own inbox started routinely exceeding 4,000 messages a day, and that was nothing compared to our customer service department. Our other policy -- reply to all legitimate messages in under 24 hours -- was being broken because no one had the time to plow through the flood of junk.

So we did what everyone else does. We started using filters.

Now the system sorts incoming mail to three piles ... probably good stuff, probably junk and almost certainly junk. We all check and reply to pile No. 1 continually throughout the day. Pile No. 2 is read twice a day, and pile No. 3 is reviewed by a human every 48 hours.

The horrible truth is, no matter how many rules and instructions we give the filters to help them know what's junk and what's not, legitimate mail still ends up in the junk box.

I have a very real horror of deleting a junk pile without carefully scrolling through looking for those needles of gold in the haystack. In fact, one time when I was out, my then-new assistant blithely deleted my junk folder to "clean up" my inbox, and lost several crucial messages that caused us a massive headache later.

However, this means we still have to review that entire massive mountain of email.

That's why I've asked our IT specialist to look for a new email filter. Most of the filter marketing pieces triumphantly discuss how much junk they stop. "97% of junk gone!" I've told IT to completely ignore that type of marketing. What we want to know about Ė and, indeed, what every customer-facing organization MUST care about is *not* how much junk is filtered, but rather how much customer mail is saved.

Because I'd rather have a few more junk messages in my inbox than risk losing a single reader letter.

And I hope that's the way your company feels about its customers as well.

So here's a question to raise at the next management meeting: "How is our email filtered?" If you're using a filter to evaluate message content or a challenge response system, then you're almost certainly losing some important customer email.

The only safe type of filter that I know of (bearing in mind I'm a marketer, not a techie) is one based on blocking IP addresses of known junk mailers.

Got any advice or stories to share on this front? We're accepting posted comments on *all* MarketingSherpa stories and Case Studies now at our site so that you can share your know-how with the community. Please post a comment to this blog, just don't be too promotional.

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Comments about this Blog Entry

Aug 21, 2006 - Tom Gray of Gray eMarketing Solutions says:
I have a client with a huge spam problem - several hundred to over a thousand a day. We implemented Cloudmark and, while it can take a while for it to process the inbox after a long weekend, it works like a charm and I've yet to find a misidentified email in its junk bin. If you're familiar with Cloudmark you know that it operates on a 'wisdom of crowds' model that relies on its user community to identify what's garbage and what's not and share it with the rest of the Cloudmark universe.

Aug 21, 2006 - Bill Ralston of Ralston Ventures says:
You're looking for a solution that offers a low false positive rate, which essentially means it will err on the side of the customers email not being spam. At the desktop or server, you can use Spam Bayes ( which works on statistics of content, something easy for a web marketing person to understand. You can also try a hosted solution like Message Labs ( or appliance like IronPort ( I'd suggest avoiding IP filtering, blacklists, or whitelists, because the majority of web users don't "own" their email servers, but instead share them with other users in a hosted environment. That also means they share an IP address, and share the blame for any spam sent by any of the 1000+ users of the hosted server. If IT can't help, it's time to get yourself a good consultant.

Aug 21, 2006 - Kathy Webb of Inc. says:
We have used a mail management system called MailWise for several years. It is very customer definable (whitelists, blacklists, spam tolerance thresholds, etc.). We get replies to client queries that generally have specific subject lines and the ad hoc query ability of MailWise lets us 'catch' the blocked mail very quickly. Best of all, they store your organization's email on their server for two weeks - an invaluable backup in the two occasions when our mail server went on the fritz. We lost ZERO mails, even when we were down two days. Kathy Webb PS. If you try them, tell them I sent you! I can win an Ipod Nano and be my daughter's hero! ;-)

Aug 21, 2006 - Alison Chandler of AAAS says:
I'm seeing an increase in people using sender verification to block spam - especially from Mindspring and Earthlink addresses. The first time you mail one someone with an Earthlink address, for example, you must go to a website and fill out a form to verify you are a human being. You also have to type in a code, much like you have to do to post a comment to this blog. While this technique may stop some legitimate mail from folks who don't take the time to fill out the form, it does a great job at blocking spam. It is certainly better than word filtering, or even statistical analysis - at least until the spammers figure out a way around it. I also agree that the Cloudmark technique is good. A similar technique is used by Yahoo! and my personal address there is virtually spam-free, though there are some false positives at times.

Aug 21, 2006 - Scott Ahlsmith, CTC of Magellan Travel Group says:
Anne, We share your feelings about e-mail filters. We receive hundreds of travel confirmation e-mail messages each day from around the world. These varied messages and numerous IP addresses fry most spam filter's algorithms Our Holy Grail was an e-mail filter with high recognition and zero false-positives. About 3 years ago we subscribed to Cloudmark ( [Full-disclosure: I don't work for Cloudmark and I do pay for their services just like all their other subscribers. No vested interest here!] We liked Cloudmark's Web 2.0 (social networking, citizenship ranking, and collaboration) approach. You can read more about this unique approach on their Web site, but Cloudmark replaces complex algorithms and AI patterns with good, old, human recognition. If you tag a message as spam and another Cloudmark user tags the same message as spam, Cloudmark treats the message as spam and your "reliability" status in the community increases. If, however, you subscribed to an e-newsletter (something other than Marketing Sherpa, of course) and one person tagged it as spam, but someone else tagged it as an opt-in subscription, Cloudmark would permit the message to pass through the community filter and would lower the "reliability" status of the citizen who mistakenly tagged the subscription newsletter as spam. The beauty of this system is that it grows smarter as the collective experience of its users grows smarter. It also stops new forms of spam and phishing within hours of their release because "it's always 5 o'clock somewhere" and someone is always watching their Inbox. This morning, out of 326 messages, Cloudmark blocked 275, and let one spam message through. I highlighted the message and clicked on the Block Spam icon in Outlook and it was removed from my Inbox and duly recorded my decision for the rest of the Cloudmark community. Now if someone would just create a citizen rating system for wiki edits, the world would be a better place! Scott Ahlsmith, CTC President & CEO Magellan Travel Group CEO

Aug 21, 2006 - David Riecks of says:
There are a lot of email filters that are based on blocking IP addresses of known junk mailers, so this exclusion method creates as many problems as it solves. The primary problem is this is all based on one giant assumption, that each domain or website has itís on mail server and each of those has a different IP address. In reality, a large number small businesses are with webhosts that use virtual hosting arrangements with shared facilities. If your business is within a shared IP, or using a shared mailserver, you can be penalized for something you didnít do. If someone else using that same mail server that you share, is accused of having sent Unsolicited Bulk Email messages (aka spam); you may find that all of your messages to your clients are getting blocked by filters using this technology. From my understanding, there are a limit to the number of IP addresses that can be assigned, so over time there will need to be more shared IP situations; or a new IP system will have to be created. While I donít have an answer for what the best method would be, I can tell you that using IP numbers is not the best or most efficient way to deal with the problem.

Aug 21, 2006 - Terri Zwierzynski of says:
Here's a spam solution that I have found that works great for me. It integrates with Outlook (but not Outlook Express), and it learns from me what I think is spam or not. For instance, when you set it up, you can instantly tell it that everyone in your address book is not spam. Then when the spam starts rolling in, you just tell it what you never want to see again...and you never see it again! The best part is, I never get something accidentally sent to the spam box that I might want to has a "Review" folder for stuff it's not sure about. Instead of sorting out spam hourly, I can visit the Review folder just once a day. And since I get emails from new people all the time, I never have to worry that I will miss an opportunity!

Aug 21, 2006 - Lee Nelson of says:
I realize my spam blocking solution is not available to everyone but it works well for a small business such as mine. First I channel mail not sent to a specific address to the trash at the ISP level. When I accidently turned this off a while back my spam count went from the typical 100-200 per day to over 6000 a day. The second thing I do is use the filtering option in Apple Mail. You obviously have to use a Macintosh for this option but I really believe that for a business that can do so there is a considerable financial benefit to using this platform. I do have to mark additional emails as spam on a daily basis but 3/4ths plus are automatically filtered and I have only found 1 incorrectly filtered email in the last 6 months. I do check the junk mail folder regularly but I can quickly skim through it.

Aug 22, 2006 - Simon de Ridder of Baker & McKenzie Amsterdam says:
Based on personal experience with my Dutch internet service provider I found out that even IP-filtering (based on addresses or ranges) is not fool proof: a year ago I suddenly did not receive e-mail anymore from a good friend in the States. After some research it turned out that my provider received a lot of spam from some users of the US-isp Juno... and they blocked the whole ip-range associated to Juno. Bottomline: even simple processes, like IP-filtering, are executed by humans.

Aug 23, 2006 - Mike Mindel of CTO says:
We use to despam all our incoming mail. The mail then gets sent through to a hosted exchange server which we access with Outlook. This works a treat. Webmail can worry about continually improving their spam filters and the hosted exchange server host can worry about maintaining exchange (sheeesh!). So we get the best of both worlds. Mike

Aug 23, 2006 - Joshua Virkler of Communion With God Ministries says:
I too have tried Cloudmark, but unlike the others here we DID experience false positives! I was dumbfounded by this. However, we did find a solution that fits us perfectly, and keeps us from losing any good messages. It's called AlienCamel. (I don't work for them or have any financial stake whatsoever.) It is simply the best system we have found. It uses multiple spam filters including a personalized baysian filter; it uses a whitelist; it uses the two best antivirus programs to check all messages; it allows you to preview messages without showing images; etc, etc, etc. I can't recommend it enough.

Sep 12, 2006 - elayne angel harbert of dakota carmel corp says:
i have a big problem with earthlink who hosts my website. evidently they are blocking mail from one of my biggest and most important vendors. they will not admit it and i cannot find any bounced emails to provide full headers. earthlink says it is a "problem with the isp" or the "server" and something about "open relay vulnerability". but they finally used the word "black list" yesterday. this company is not a spammer. they do utilize email to market themselves, but not to the average joe down the street. they are satellite transponder space resellers and work with very prestigious broadcasters. i do not understand the problem. any ideas? thanks. angel

Apr 26, 2011 - Judy Sullivan of Magnet Nurse Leaders says:
My web hosting company, IPage, uses Cloudmark. For no apparent reason, Cloudmark has determined that I am a spammer and my outgoing emails have been blocked in perpetuity. Last week I sent out a group of about 35-50 emails and the body of the email message disappeared and arrived blank. That is the only thing that I know of to cause this but I have no way to find out why I have been blocked and what I can do to rectify it. Other than that, I am not a volume emailer. All suggestions welcome. Cloudmark does not seem to have a way to address this. Judy Sullivan

Apr 29, 2011 - Adam T Sutton of MarketingSherpa says:
Hi Judy -- I am sorry to hear about your troubles. Two things you can try: 1. Reach out IPage to understand the situation and ask if there are steps you can take to solve the problem. 2. Set up a "seed list" of email accounts you maintain for various addresses. You can send test emails to this list to uncover deliverability or rendering issues before sending the emails to your contacts. You can also get a lot of great information on deliverability in this webinar replay (open access until May 6): . Good luck!

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