Tagfilters

Message not compliant with the RFCs

Every once in a while we’ll see a rejection from Yahoo that says RFCs 554 5.0.0 Message not accepted due to failed RFC compliance. What does that mean and what can we do about it? It really does mean exactly what it says on the label: there’s something about the message that is not in compliance with any number of RFCs and are not going to accept the message in its current state. When...

Step by Step guide to fixing Gmail delivery

I regularly see folks asking how to fix their Gmail delivery. This is a perennial question (see my 2019 post and the discussions from various industry experts in the comments). Since that discussion I haven’t seen as much complaining about problems. There are steps that work to get delivery fixed at Gmail. Verify that your mail is actually going to bulk. I had one client that had a bad /...

Misinformation on filters

I’ve seen reports that someone is asserting that utm=COVID19 in URLs results in all mail going to bulk at multiple ISPs. This is the type of thing that someone says is true and dozens of folks believe it and thus a “deliverability phact” is born. For a plethora of reasons, this doesn’t pass the sniff test. Don’t believe everything you read on the internet. It’s...

Discussion Session

More than 30 people joined our delivery discussion from last Wednesday evening (Irish time). Thanks to all who joined and participated. I had a number of different topic suggestions, but the thing on everyone’s mind was the current pandemic and how much email many of our customers, clients, and companies are sending. We had what I think was a productive discussion sharing information and...

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?” 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...

Same MX, different filters

One of the things I do for clients is look at who is really handling mail for their subscribers. Steve’s written a nifty tool that does a MX lookup for a list of domains. Then I have a SQL script that takes the raw MX lookup and categorizes not by the domain or even the MX, but by the underlying mail filter. Part of that script classifies domains hosted by Google apps as a separate filter...

Troubleshooting delivery problems

Everyone has their own way of troubleshooting problems. I thought I would list out the steps I take when I’m trying to troubleshoot them. Clarify the problem. As a consultant, folks come to me asking me to help them solve their delivery problems. My first step is to get them to clarify what symptoms they’re seeing. Something happened to make them contact me, and that’s where we...

Mentally modelling filters

When we talk about filters, we often think there is one filter. But, in many cases there are multiple stages of filters, each examining mail in a different way. In deliverability terms the easiest filters to ignore are the individual user filters. Mostly because there’s nothing we can do about those. These are the baysean style filters built into a lot of email clients as well as specific...

Spam is never timely nor relevant

One of the ongoing recommendations to improve deliverability is to send email that is timely and relevant to the recipient. The idea being that if you send mail a recipient wants, they’re more likely to interact with it in a way that signals to the mailbox provider that the message is wanted. The baseline for that, at least whenever I’ve talked about timely and relevant, is that the...

Barracuda update

The Barracuda twitter account has been very helpful and responsive to the issue. A few hours ago they tweeted that the problem should have been fixed. 1) Hi all, sorry to take so long to get the info. First, there was a routine transient spike in blacklisted IPs as part of the threat analysis process. It normally goes unnoticed. However in this case…— Barracuda Networks (@barracuda)...

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