I do not think that means what you think it means

Yesterday, I looked at the analysis of ESP delivery done by Mr. Geake. Today we’ll look at some of his conclusions.
“Being blacklisted most likely suggests that sender IP either sends out to a great deal of unknown or angry recipients.” That’s not how most blocklists work. Most blocklists are driven by spam traps or by the personal mailboxes of the list maintainers. The only blocklist that took requests from the public was the old MAPS RBL, and I don’t believe that is the case any longer.
Blocking at ISPs is often a sign of sending out a lot of mail to unknown or angry / unengaged recipients. But most ISPs don’t make their lists public. Some allow anyone to look up IP addresses, and if we had the IPs we could check. But we don’t, so we can’t.
“[…] if you share this IP with Phones4U then only 62% of your emails will be accepted by a recipient’s email server. That’s before they hit the junk filter. I wouldn’t want to pay for that.” This conclusion relies on the Sender Score “accepted rate” number. Accepted Rate is a figure I don’t rely on for much. I’ve never been able to reconcile this number with what client logs tell me about accepted rate. For instance, I have one IP address that has a 4.4% acceptance rate. But I know that 19 out of 20 emails from this IP do not bounce. In fact, it’s rare to see any mail from this IP bounce.
The one thing that Mr. Geake gets right, in all of this, is that if you’re on a shared IP address with a poor sender, then you share that sender’s reputation. Their reputation can hurt your delivery.
But a dedicated IP isn’t always your best bet, either.  Smaller senders may not have the volume or frequency required to develop and keep a good reputation on an static IP. In these cases, sharing an IP address with similar senders may actually increase delivery.
For some senders outsourcing the email expertise is a better use of resources than dedicating a person to managing email delivery. For other senders, bringing mail in house and investing in staff to manage email marketing is better.
Tomorrow: how do you really evaluate an ESP?

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Return Path speaks about Gmail

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Blocklist BCP

As many of you may be aware there is a draft document working its way through the Internet Research Task Force (IRTF) discussing best common practices for blocklists. The IRTF is a parallel organization to the IETF and is charged with long term research related to the Internet. The Anti-Spam Working Group was chartered to investigate tools and techniques for dealing with spam.
Recently the ASRG posted a draft of a best practices document aimed at those running blocklists (draft-irtf-asrg-bcp-blacklists-07). This document has been under development for many years. The authors have used this document to share their experiences with running blocklists and their knowledge of what works and what doesn’t.
Best practices documents are never easy to write and consensus can be difficult. But I think that the authors did a good job capturing what the best practices are for blocklists. I do support the document in principle and, in fact, support many of the specific statements and practices outlined there. As with any best practices documents it’s not perfect but overall it reflects the current best practices for blocklists.
Ken Magill’s article about the BCP
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Are blocklists always a good decision?

One of the common statements about blocklists is that if they have bad data then no one will use them. This type of optimism is admirable. But sadly, there are folks who make some rather questionable decisions about blocking mail.
We publish a list called nofalsenegatives. This list has no website, no description of what it does, nothing. But the list does what it says it does: if you use nofalsenegatives against your incoming mailstream then you will never have to deal with a false negative.
Yes. It lists every IP on the internet.
The list was set up to illustrate a point during some discussion many years ago. Some of the people who were part of that discussion liked the point so much that they continued to mention the list. Usually it happens when someone on a mailing list complained about how their current spamfiltering wasn’t working.
Some of the folks who were complaining about poor filtering, including ones who should know better, did actually install nofalsenegatives in front of their mailserver. And, thus, they blocked every piece of mail sent to them.
To be fair, usually they noticed a problem within a couple hours and stopped using the list.
This has happened often enough that it convinced me that not everyone makes informed decisions about blocking. Sure, these were usually small mailservers, with maybe a double handful of users. But these sysadmins just installed a blocklist, with no online presence except a DNS entry, without asking questions about what it does, how it works or what it lists.
Not everyone makes sensible decisions about blocking mail. Our experience with people using nofalsenegatives is just one, very obvious, data point.

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