Tagfiltering

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 my 2013 post. The power and the complexity of filters in even greater now than then...

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 keep fighting the good fight to make it better. As always, I’m interested in filters and how...

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 blog post pointing out the problems with the comment. Today a comment from Joe King showed...

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 or rejected. AHBL is managed by The Summit Open Source Development...

URL reputation and shorteners

A bit of  a throwback post from Steve a few years ago. The problem has gotten a little better as some shortening companies are actually disabling spammed URLs, and blocking URLs with problematic content. I still don’t recommend using a public URL shortener in email messages, though. Any time you put a URL in mail you send out, you’re sharing the reputation of everyone who uses URLs with...

The long tail of domains

I frequently get clients telling me that they have about 15 (20, 30) major domains on their list, and then a long tail of domains with only a couple of recipients. If you sort simply by the left hand side of the @, that’s true. When you’re sending email, it’s not just the domain in the email address that is important. Of equal importance is the MX. The MX is what actually...

Superstition, correlation and reality

I’m not a huge baseball fan, probably a side effect of growing up in a city with no MLB team. But I do enjoy the social aspects of rooting for local teams when they’re winning big games. Last night I was following the World Series score online and switched over to watch the last inning. I posted something about the game on FB just about 30 seconds before the Giant’s outfield...

Content based filtering

Content filtering is often hard to explain to people, and I’m not sure I’ve yet come up with a good way to explain it. A lot of people think content reputation is about specific words in the message. The traditional content explanation is that words like “Free” or too many exclamation points in the subject line are bad and will be filtered. But it’s not the words...

Typo traps

People make all sorts of claims about typo traps. One claim that showed up recently was that Spamhaus has just started using typo traps. I asked my Facebook network when people started using typos to detect incoming spam. Two different colleagues mentioned using typos, both on the left hand side and the right hand side, back in ’98 and ’99. The point is, typo traps are absolutely...

Don't wait to address delivery problems

One of the worst ways to deal with blocking issues is to ignore them and hope your mail magically moves from the bulk folder back into the inbox. While this does happen as ISPs and filter companies update their filters, it’s not that common and it’s usually the result of a sender actually cleaning up their sending processes and improving the quality of the mail they send. Do not...

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