Tag: filtering

Trawling through the junk folder

As a break from writing unit tests this morning I took a few minutes to go through my junk folder, looking for false positives for mail delivered over the past six weeks. We don’t do any connection level rejection here, so any mail sent to me gets delivered somewhere. Anything that looks like malware gets […]

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Confusing the engineers

We went camping last weekend with a bunch of friends. Had a great time relaxing on the banks of the Tuolumne River, eating way too much and visiting. On Saturday I was wearing a somewhat geeky t-shirt. It said 554: abort mission. (Thank you MessageSystems). At some point on Saturday every engineer came up to me, […]


Do system administrators have too much power?

Yesterday, Laura brought a thread from last week to my attention, and the old-school ISP admin and mail geek in me felt the need to jump up and say something in response to Paul’s comment. My text here is all my own, and is based upon personal experience as well as those of my friends. That […]


Politics and Delivery

Last week I posted some deliverability advice for the DNC based on their acquisition of President Obama’s 2012 campaign database. Paul asked a question on that post that I think is worth some attention. I am fascinated by the ramifications of email deliverability for political donations. Are there sysadmins at the big ISPs who make […]

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June 2015: the Month in Email

Happy July! We are back from another wonderful M3AAWG conference and enjoyed seeing many of you in Dublin. It’s always so great for us to connect with our friends, colleagues, and readers in person. I took a few notes on Michel van Eeten’s keynote on botnets, and congratulated our friend Rodney Joffe on winning the […]

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Filtering more than spam

The obvious application of machine learning for email is to send spam to the junk/bulk folder. Most services use some level of machine learning for filters. Places like Gmail have extensive machine learning filters to filter spam and unwanted mail away from their users. Some organizations are taking the filtering process a step further. Almost […]


Deliverability and IP addresses

Almost 2 years ago I wrote a blog post titled The Death of IP Based Reputation. These days I’m even more sure that IP based reputation is well and truly dead for legitimate senders. There are a lot of reasons for this continued change.  Improved computing power I touched on the increase in computing power in […]


January 2015 – The Month in Email

It’s February already! January went fast, right? At WttW, we are gearing up for MAAWG SF later this month — will we see you there? We started the year with a set of predictions about email. Mostly we think email will continue to be great at some things and not-so-great at other things, and we’ll […]

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Email filtering: not going away.

I don’t do a whole lot of filtering of comments here. There are a couple people who are moderated, but generally if the comments contribute to a discussion they get to be posted. I do get the occasional angry or incoherent comment. And sometimes I get a comment that is triggers me to write an entire […]


AHBL Wildcards the Internet

AHBL (Abusive Host Blocking List) is a DNSBL (Domain Name Service Blacklist) that has been available since 2003 and is used by administrators to crowd-source spam sources, open proxies, and open relays.  By collecting the data into a single list, an email system can check this blacklist to determine if a message should be accepted […]

  • Lost in the mists of time

    Over on the Farsight Security blog Joe St. Sauver talks about some of the early days of online abuse, on usenet. Laura and I were on the periphery of early usenet abuse, mostly as users, but Usenet (and IRC) around then were the places we both started with email abuse.No Comments

  • Ongoing Yahoo delays

    I've been hearing from folks over the last few days that they're seeing an uptick in deferrals from Yahoo! The deferrals are not uniform. ESPs report they're seeing some, but not all, customers affected. Other ESPs aren't seeing any changes. It's not just you. But it would be very worthwhile to dig into engagement and other stats. It's possible this is a new normal at Yahoo! and they're tightening filters to catch mail that doesn't fit their standards but was previously difficult to filter.No Comments

  • AOL starts using Sender Score Certification

    Good news for Sender Score Certified IPs. Return Path recently announced that AOL has joined the list of ISPs offering preferential treatment to certified IPs.  1 Comment