Troubleshooting: part 3

As I continue to think about how people troubleshoot email delivery I keep finding other things to talk about. Today we’re going to talk about the question most folks start with when troubleshooting delivery. “Did ISP change something?”

image of a head with gears and ideas floating around it

At least once a week I check some delivery or email fora and some form of the question is sitting there.

“Did X change something? We haven’t done anything different and our delivery went way down overnight.”

Did Y change their filters? Our delivery is tanking and all our authentication is fine.”

Anyone hear of a change at Z? We have been having increasing difficulty reaching the inbox and we don’t understand why. Looking for suggestions.

In reality, the answer to this question Does Not Matter and asking it is only going to delay actually resolving your delivery issue.

When filters change

The reality is, filters are continually changing. ISPs and filtering companies are always tuning filters. These changes are roughly in 3 categories.

  • Ongoing tweaking and improvement to provide a better experience for their users
  • Changes done to address a emergent threat (Yahoo deploying p=reject is one example of this)
  • Specific changes to catch a type of spam they had previously been unable to effectively identify and filter.

Filters are not static. They are continually adjusting based on a number of things. We can always assume the answer to the question is yes. Something changed. Now what?

There are basically 3 situations here.

  • The filters did something unexpected and caught mail it wasn’t intended to catch, causing recipients to complain to the ISP.
  • The filter change was intentional but caught more mail than was intended, causing recipients to complain to the ISP.
  • The filter change was intentional and caught exactly the mail that was intended and the recipients didn’t care enough to notice that mail was missing.

In the first two cases, the ISP is going to fix things. They’re going to listen to their users and adjust the filters. In the first case, I expect to see changes and rollback within 24 – 48 hours. In the second, I expect to see changes in 24 – 96 hours.

The third case is the interesting one. Does anyone care about mail they don’t care about going to the bulk folder? Folks sending mail, even opt-in mail, that the users don’t complain about when it’s missing is the definition of grey mail. Filter maintainers listen to their users. If users complain they’ll change things, if users don’t complain they’ll assume the filters are working as intended.

The answer to the question did the filters changed tells you nothing. Of course the filters changed. Either they’re doing something that the maintainers don’t intend, which means they’ll be fixed or they’re catching mail they’re intended to catch.

Instead of asking if the filters changed, flip the question. Why are my users not interested enough in my mail to notice it when it’s gone? Start your troubleshooting from that perspective.

Related Posts

Thoughts on "ISP relations"

I’ve been thinking a lot about the field of ISP relations and what it means and what it actually is. A few years ago the answer was pretty simple. ISP relations is about knowing the right people at ISPs in order to get blocks lifted.
The fact that ISPs had staff just to deal with senders was actually a side effect of their anti-spam efforts. In many places blocking was at least partially manual, so there had to be smart, technical, talented people to handle both the blocking and unblocking. That meant there were people to handle sender requests for unblocking.
Spam filters have gotten better and more sophisticated. Thus, the ISPs don’t need smart, technical, talented and expensive people in the loop. Most ISPs have greatly scaled back their postmaster desks and rely on software to handle much of the blocking.
Another issue is that some people on the sender side rely too heavily on the ISPs for their data. This makes the ISP reps, and even some spam filtering company reps, reluctant to provide to much help to senders. I’ve had at least 3 cases in the last 6 months where a sender contacted me to tell me they had spoken with someone at an ISP or filtering company and were told they would get no more help on a particular issue. In talking with those reps it was usually because they were drowning under sender requests and had to put some limits on senders.
All of this means ISP Relations is totally different today than it was 5 years ago. It’s no longer about knowing the exact right person to contact. Rather it’s about being able to identify problems without ISP help. Instead of being able to ask someone for information, ISP Relations specialists need to know how to find data from different sources and use that data to identify blocking problems. Sure, knowing the right person does help in some cases when there’s an obscure and unusual issue. But mostly it’s about putting together any available evidence and then creating a solution.
We still call it “ISP Relations” but at a lot of ISPs there is no one to contact these days. I think the term is a little misleading, but it seems to be what we’re stuck with.

Read More

Who are mimecast?

Mimecast is a filter primarily used by businesses. They’re fairly widely used. In some of the data analysis I’ve done for clients, they’re a top 10 or top 20 filter.
Earlier today someone asked on Facebook if mimecast may be blocking emails based on the TLD. The short answer is it’s unlikely. I’ve not seen huge issues with them blocking based on TLD of the domain. They’re generally more selective than that.

The good news is mimecast is really pretty good about giving you explanations for why they’re blocking. They’ll even tell you if it’s mimecast related or if it’s a specific user / user-company block.
Some example rejection messages from a recent dive into some bounce logs.

Read More

Email filters and small sends

Have you heard about the Baader-Meinhoff effect?

The Baader-Meinhof effect, also known as frequency illusion, is the illusion in which a word, a name, or other thing that has recently come to one’s attention suddenly seems to appear with improbable frequency shortly afterwards (not to be confused with the recency illusion or selection bias). Baader–Meinhof effect at Wikipedia

There has to be an corollary for email. For instance, over the last week or so I’ve gotten an influx of questions about how to fix delivery for one to one email. Some have been from clients “Oh, while we’re at it… this happened.” Others have been from groups I’m associated with “I sent this message and it ended up in spam.”

Read More