BLOG

Tag: filters

April 2016: The Month in Email

We are finishing up another busy month at WttW. April was a little nutty with network glitches, server crashes, cat woes, and other disruptions, but hopefully that’s all behind us as we head into May. I’ll be very busy in May as well, speaking at Salesforce Connections in Atlanta and the Email Innovation Summit in […]

No Comments

Insight into Gmail filtering

Last week I posted a link to an article discussing how Gmail builds defenses to protect their users from malicious mail. One of the things I found very interesting in that article was the discussion about how Gmail deploys many changes at once, to prevent people from figuring out what the change was. Let’s take a […]

3 Comments

Thoughts on filters

One of the questions we received during the EEC16 closing keynote panel was why isn’t there a single blocklist that everyone uses and why don’t ISPs share data more. It would be so much easier for senders if every ISP handled mail the same as every other. But the world isn’t that simple, and it’s not […]

No Comments

Purchased lists and ESPs: 9 months later

It was about 8 months ago I published a list of ESPs that prohibit the use of purchased lists. There have been a number of interesting responses to that post. ESPs wanted to be added to the list The first iteration of the list was crowdsourced from different ESP representatives. They shared the info they […]

5 Comments

Troubleshooting delivery is hard, but doable

Even for those of us who’ve been around for a while, and who have a lot of experience troubleshooting delivery problems things are getting harder. It used to be we could identify some thing about an email and if that thing was removed then the email would get to the inbox. Often this was a domain […]

1 Comment

November 2015: The month in email

As we head into the last month of the year, we look back at our November adventures. I spoke twice this month, first at Message Systems Insight in Monterey (my wrap-up post is here) and then with Ken Magill at the  at the 2015 All About eMail Virtual Conference & Expo (a short follow-up here, […]

No Comments

When did the reject happen?

Earlier today I approved a comment from Mike on a post about problems at AOL from 2012. The part of the comment that caught my attention: SMTP error from remote mail server after end of data: 521 5.2.1 : AOL will not accept delivery of this message. Mike also mentioned his IP reputation is good, […]

6 Comments

DOD breaks links in .mil clients

The Department of Defense is breaking HTML links in mail to .mil domains. This is part of the DoD’s attempt to curtail phishing. a great majority of intrusions into Pentagon networks are the result of the kind of human error that is exploited in phishing attacks, in which seemingly trustworthy e-mail links are used as attack […]

3 Comments

Filter complexity

During the Q&A last week, I mentioned an example of a type of filter trying to demonstrate how complex the filters are. There was some confusion about what I was saying, so I thought I’d write a blog post explaining this. Background This story came from another deliverability person, let’s call her ESPer. One of […]

No Comments

Thanks for the great session

I had a great time answering questions at the 2015 All About eMail Virtual Conference & Expo today. Thanks so much to everyone who participated and asked questions. They were great and I’m sorry we didn’t have more time. I did get some questions on twitter (@wise_laura) afterwards. One was about an example I gave to […]

1 Comment
  • HE.net DNS problems

    Hurricane Electric had a significant outage of their authoritative DNS servers this morning, causing them to return valid responses with no results for all(?) queries. This will have caused delivery problems for any mail going to domains using HE.net DNS - which will include some of their colocation customers, as well as users of their free services - but also will have caused reverse DNS to fail for most servers hosted by Hurricane Electric worldwide, so if any of your mail is being sent from HE hosted machines you may have seen problems. (We're HE customers so we noticed. Still happy with them as a vendor.)No Comments


  • 65.0.0.0/8 DNS issues

    If you're sending email from any address beginning with a 65 - in 65.0.0.0/8 - it's possible you'll see some delivery problems. Something appears to be broken with dnssec signatures for the reverse DNS zone, leading queries for reverse DNS to fail for anyone using a dnssec aware DNS resolver (which is almost everyone).1 Comment


  • Our green bar certificate is going away

    Later today we'll be switching from an Extended Validation ("green bar") SSL certificate to a Domain Validation certificate. This isn't exactly a planned change but I'm waiting for responses from Comodo before I go into it too much. I'll share some more details next week.3 Comments


Archives