At least one ESP and Spamhaus are currently investigating bounce messages at a couple ISPs incorrectly pointing to Spamhaus as the reason for the block. The bounce messages are taking the form: smtp; 554 p3plibsmtp03-07.prod.phx3.secureserver.net bizsmtp IB105. Connection refused. 192.0.2.24 is listed on the Exploits Block List (XBL) <; Please visit for more information. smtp; 553 5.7.1 [BL21]...
One of the ongoing challenges sending email, and managing a high volume outbound mail server is dealing with the ongoing changes in filtering. Filters are not static, nor can they be. As ISPs and filtering companies identify new ways to separate out wanted email from unwanted email, spammers find new ways to make their mail look more like wanted mail. This is one reason traps are useful to...
There was a discussion today on a marketing list about role accounts and marketing lists. Some ESPs block mail to role accounts, and the discussion was about why and if this is a good practice. In order to answer that question, we really need to understand role accounts a little more. What are role accounts? A definition I tend to use is role accounts are email addresses that map to a business...
It seems one of the most asked questions I hear from people is about filters and what the secret sauce is. Cloudmark’s processes which determine which IPs get a poor or suspect reputation in our CSI products, take into account many different factors, including both spam trap hits and volume of trusted end user complaints (hitting the “This is spam” button), reputation of the reverse DNS of the...
While discussing a draft of a Deliverability BCP document the issue came up of what rejections at different phases of the email delivery transaction can mean. That’s quite a big subject, but here’s a quick cheat sheet. At initial connection Dropped or failed connection: your reputation with the receiver is so bad that they don’t want to see any email from you, ever their mail...
IP reputation is a measure of how much wanted mail a particular IP address sends. This wanted mail is measured as a portion of the total email sent from that IP. Initially IP reputation was really the be all and end all of reputation, there was no real good way to authenticate a domain or a from address. Many ISPs built complex IP reputation models to evaluate mail based on the IP that sent the...
Over the last few months more and more marketers are finding their primary delivery challenge is the Gmail inbox. I’ve been thinking about why Gmail might be such a challenge for marketers. Certainly I have gotten a lot of calls from people struggling to figure out how to get into the Gmail inbox. I’ve also seen aggressive domain based filtering from Gmail, where any mention of a...
Last week at M3AAWG representatives from AOL, Yahoo, Gmail and Outlook spoke about their anti-spam technologies and what the organizations were looking for in email. This session was question and answers, with the moderator asking the majority of the questions. These answers are paraphrased from my notes or the MAAWG twitter stream from the session. What are your biggest frustrations? AOL: When...
Most delivery experts will tell you that ISPs measure recipient engagement as a part of their delivery. That’s absolutely true, but I think there’s a language difference that makes it hard for senders to understand what we mean by engagement. ISPs, and other filtering companies, profile their user base. They know, for instance, who logs in and checks mail every day. They know who...
Last week I blogged about the changes at ISPs that make “ISP Relations” harder for many senders. But it’s not just ISPs that are making it a little more difficult to get answers to questions, some spam filtering companies are pulling back on offering support to senders. For instance, Cloudmark sent out an email to some ESPs late last week informing them that Cloudmark was...
RSS - Posts