Return Path on Content Filtering

Return Path have an interesting post up about content filtering. I like the model of 3 different kinds of filters, in fact it’s one I’ve been using with clients for over 18 months. Spamfiltering isn’t really about one number or one filter result, it’s a complex interaction of lots of different heuristics designed to answer the question: do recipients want this kind of mail?

Related Posts

Delivery challenges increasing

Return Path published their most recent Global Deliverability report this morning. (Get the Report) This shows that inbox placement of mail has decreased 6% in the second half of 2011. This decrease is the largest decrease Return Path has seen in their years of doing this report.
To be honest, I’m not surprised at the decrease. Filters are getting more sophisticated. This means they’re not relying on simply IP reputation for inbox delivery any longer. IP reputation gets mail through the SMTP transaction, but after that mail is subject to content filters. Those content filters are getting a lot better at sorting out “wanted” from “unwanted” mail.
I’m also hearing a lot of anecdotal reports that bulk folder placements at a couple large ISPs increased in the first quarter of 2012. This is after the RP study was finished, and tells me increased bulk folder placement is more likely to be a trend and not a blip.
One of the other interesting things from the RP study is that the differences are not across all mail streams, but are concentrated in certain streams and they vary across different regions.

Read More

First step in delivery

Ever trawl through your logs and notice that there is a delivery problem somewhere? I’m sure everyone sending email in any volume has.
What’s the first thing you do when you discover a block?

Read More

Things Spammers Do

Much like every other day, I got some spam today. Here’s a lightly edited copy of it.
Let’s go through it and see what they did that makes it clear that it’s spam, which companies helped them out, and what you should avoid doing to avoid looking like these spammers…

Read More