A c/p from an email I sent to a mailing list. I think we’re seeing a new normal, or are still on the pathway to a new normal. Here’s my theory. 1) Hotmail made a lot of underlying code changes, learning from 2 decades of spam filtering. They had a chance to write a new codebase and they took it. 2) The changes had some interesting effects that they couldn’t test for and didn’t expect. They spent...
A quick post to say that posting will be light the next few weeks. I’m off later this week to visit Dublin. After I get back from that I’m headed to Chicago to speak at ACTIVATE hosted by Active Campaign. If you register by tomorrow you can use the code ACTIVATE and get in for $200. It’s looking like a good conference. I’ll be speaking about deliverability, specifically...
We often say that a blacklist has “listed the world” when it shuts down ungracefully. What exactly does that mean, and why does it happen? Blacklists are queried by sending a DNS lookup for an A record, just the same as you’d find the address of a domain for opening a webpage there. The IP address or domain name that’s being queried is encoded in the hostname that’s...
A decade or so ago I was offering whitelisting services to clients. It was pretty simple. I’d collect a bunch of information and do an audit on the customer’s sending. They’d get a report back identifying any issues that would limit their chances at acceptance. Then I’d go and fill in the forms on behalf of the client. Simple enough work, and it made clients feel better...
FADE IN EMAILGEEKS.SLACK.COM #email-deliverability It is morning in the channel. The regular crowd is around discussing the usual. JK, smart, competent head of deliverability at an ESP asks: Anyone familiar with SECTOOR EXITNODES listings and have insight into what’s going on if listed? ME: Uh, that’s the Tor Exit Nodes list. They think your IP is used by Tor. That’s all sorts...
It is a regular occurrence that senders ask filters and ISPs for mitigation. But there seems to be some confusion as to what mitigation really means. I regularly hear from senders who seem to think that once they’ve asked for mitigation that they don’t have to worry about filtering or blocking at that ISP for a while. They’re surprised when a few weeks or even days after they...
A bit of advice from the folks at the CBL, posted with permission and some light editing. I’ve been seeing some folks report longer connection times at some places, and this might explain some of it. It’s certainly possible, even likely, that the large ISPs are getting a lot of this kind of traffic. A botnet, likely a variant of cutwail, has been for the past several years been...
RSS - Posts