Horses, not zebras

I was first introduced to the maxim “When you hear hoofbeats, think horses not zebras” when I worked in my first molecular biology lab 20-some-odd years ago. I’m no longer a gene jockey, but I still find myself applying this to troubleshooting delivery problems for clients.
It’s not that I think all delivery problems are caused by “horses”, or that “zebras” never cause problems for email delivery. It’s more that there are some very common causes of delivery problems and it’s a more effective use of time to address those common problems before getting into the less common cases.
This was actually something that one of the mailbox provider reps said at M3AAWG in SF last month. They have no problem with personal escalations when there’s something unusual going on. But, the majority of issues can be handled through the standard channels.
What are the horses I look for with delivery problems.

  1. Technical issues. These are actually getting rarer as companies move to the designed-for-bulk MTAs like MessageSystems and Port25. But they’re still worth checking and can contribute to delivery problems. Luckily, technical issues are often the easiest to solve, and once they’re solved usually stay solved.
  2. Content issues. These are getting much more common as ISPs start looking at all the URLs and links in emails, including the landing pages.  Gmail, for instance, does almost all their filtering based on content rather than originating IP. This is not that difficult to solve, but can be harder to solve than technical issues.
  3. Address collection issues. Most delivery problems start at the point of address collection, and these can be challenging problems to solve. Not only do you have to solve the problem moving forward, you also have to decide what to do with the addresses you’ve previously collected. And the problems are only solved as long as someone knows why things are done the way they are.

 

Best practices: A Gmail Perspective
What goes into successful email campaigns?

Related Posts

Weird mail problems today? Clear your DNS cache!

A number of sources are reporting this morning that there was a problem with some domains in the .com zone yesterday. These problems caused the DNS records of these domains to become corrupted. The records are now fixed. Some of the domains, however, had long TTLs. If a recursive resolver pulled the corrupted records, it could take up to 2 days for the new records to naturally age out.
Folks can fix this by flushing their DNS cache, thus forcing the recursive resolver to pull the uncorrupted records.
EDIT: Cisco has published some more information about the problem. ‘Hijacking’ of DNS Records from Network Solutions

Read More

This month in email: February 2014

After a few months of hiatus, I’m resurrecting the this month in email feature. So what did we talk about in February?
Industry News
There was quite a bit of industry news. M3AAWG was in mid-February and there were actually a few sessions we were allowed to blog about. Gmail announced their new pilot FBL program. Ladar Levinson gave the keynote talking about the Lavabit shutdown and his new darkmail program. Brian Krebs won the Mary Litynski award for his work in investigating online security issues. The 4 major mailbox providers talked about their spam filters and spam filtering philosophy.
February was also the month where different companies evaluated their success or failure of products. LinkedIn announced the shutdown of their Intro product and Facebook announced the shutdown of their Facebook.com email service.
Security Issues
Cloudmark published their 2013 report on the Global Spam Threat and we discovered that the massive Target breach started through phishing. I also noticed a serious uptick in the amount of phishing mails in my own mailbox. There is  new round of denial of service attacks using NTP amplification. We provided information on how to secure your NTP servers.
Address Collection
The Hip Hop group De La Soul released their entire catalog for free, online, using a confirmed opt-in email process. On the flip side, the M3AAWG hotel required anyone logging into the wifi network to give an email address and agree to receive marketing mail. We also discovered that some political mailing lists were being used in ways the politicians and recipients didn’t expect.
Email Practices
I talked about how to go about contacting an ISP that doesn’t have a postmaster page or a published method of contact. Much of that information is actually relevant for contacting ISPs that do have a contact method, too. Finally, I talked about how ISPs measure engagement and how that’s significantly different from how ESPs think it is.
 

Read More

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?

Read More