A number of people have mentioned over the last couple weeks that they’re seeing a spike in Yahoo rejecting mail with
554 delivery error: dd Requested mail action aborted
Discussions on various mailing lists indicate these messages are related to inactive accounts. Addresses that bounce at Yahoo with these codes should be handled as inactive addresses and removed from future mailings.
It should be easy, right? Except it’s not. So why is it so hard?
With one-on-one or one-to-few email it’s pretty simple. The rejections typically go back to a human who reads the text part of the rejection message and adapt and makes the decision about future messages. The software handles what to do with the undeliverable message based on the SMTP response code.
In the case of a 5xy response the server stops attempting delivery and alerts the original sender the mail failed. One example from helping a client troubleshoot a delivery problem recently.
There’s useful information in the text portion of this email from my mail server. It says there was a permanent failure (550) and that my message won’t be delivered. It also says the email is quarantined in reply to the end of DATA. That’s actually a critical piece of information. It means Barracuda saw the entire message before deciding to reject it. It’s likely a problem with the content of the email and so I need to look at links in the message.
This type of plain text explanation is great for a human to read and act on. But it’s not that simple for list handling software to identify the relevant information in the text message and act on future emails to that recipient. Different MTA vendors and ESPs have done a lot of work to try and correctly parse bounce messages to pull out relevant information.
ISPs have tried to help the situation by giving more descriptive rejection messages. They’re still using the SMTP required 3 digit numbers, but they include short, parseable codes in the text portion of the message. In many cases they also include URLs and links that open up webpages explaining the meaning of the code. They even post a list of the most common codes on their postmaster webpages.
All of these things make it somewhat easier to handle bounces automatically. Kinda.
I’ve been working on some bounce handling recommendations for a client using a few different ESPs. I spent a good few days digging into the bounces returned by their different ESPs. It was an interesting exercise as it demonstrated how very differently ESPs handle bounces. But it also clarified for me that there are a lot of different kinds of bounces.
We’ve returned from London, where I spoke at the Email Innovations Summit and enjoyed a bit of vacation. My wrap-up post also mentions an article I wrote for the Only Influencers site, which looks at questions I get asked frequently: “Why does spam make it to the inbox and our legitimate marketing email doesn’t? Should we just copy their tactics?”
In industry news, Yahoo caught our attention for two surprising moves: disabling forwarding and — much more disturbing — creating software for intelligence agencies to search customer email.
Some legal updates this month: The Second Court of Appeals upheld an earlier ruling that companies are in fact liable for the activities of their affiliates, including spam and fraudulent claims. This is important, as we often see spammers and cybercriminals use affiliates to distance themselves from these activities. We also saw another fine assessed for a violation of CASL, and noted with appreciation the transparency and thoughtful process that the Canadian Radio-television and Telecommunications Commission (CRTC) demonstrates in explaining their actions.
Another excellent report is the one created by the Exploratorium to explain their recent experience with being phished. It’s a good piece to share with your organization, in that it reminds us that these cybercriminals are exploiting not just our technology but our trust-based connections to our friends and colleagues. It’s important to raise awareness about social engineering as a part of information security. And speaking of email security, we were delighted to note that André Leduc received the 2016 J.D. Falk award this month at M3AAWG for his excellent work on this topic. It’s a fitting legacy to our friend, J.D., who died five years ago this month. We miss him.
Finally, we’d be remiss in observing Halloween without a post about zombies. Feel free to read it aloud in your spookiest voice.
Today it was revealed that Yahoo has been scanning people’s email for the federal government.
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