Subscription Mailbombing: Must Read

SendGrid's Paul Kincaid-Smith's has a post up this morning about the "tsunami of unwanted email" generated by the bad guys out there using botnets to subscription bomb (aka harass) people and why you should secure subscription signup forms.

The bad news is, this abuse causes problems for otherwise good email senders. You didn't cause it, but you'll get caught up in it, if you don't take precautions. If you have an email signup form out there in the wild, it's time to add a bit of security to it to prevent the pain you'll run into if and when you get Spamhaus blacklisted because your signup page got abused.

TL;DR? If you have an email signup form, you need to enable COI/DOI (double opt-in) and also add a CAPTCHA-like process (reCAPTCHA is recommended), or else when the botnet bad guys get to you, they're going to sign lots of people up to your lists who don't want to be there, and pain is sure to follow.

Gmail providing easy-to-read Auth Results


This is pretty slick. When is the last time you selected "View Source" in Gmail to look at the raw headers and body content of an email message? As of a couple of days ago, Google has added some nice new info to this feature, showing an easy-to-understand summary of authentication results. In this example, it's highlighting that SPF, DKIM and DMARC are all working correctly.

This is all info you could find by looking through the email headers. But it's nice to see it called out in this way; it saves some digging and gives you a very clear understanding of how the Gmail platform sees the message.

List Unsubscribe in Apple's iOS 10

As I mentioned before, Apple has provided support for the "list-unsubscribe" header in the built-in mail client on the latest version of their mobile platform, iOS 10. Now that iOS 10 has been released to the world, I've reviewed how this process works and put together what I think you need to know.

Doing the Math on Purchased Lists

Back in 2014, MailChimp published data showing what happens when you mail to purchased lists. Though it is now a couple of years old, it's still solid research and quite relevant today.

Bye bye, SmartScreen

Microsoft recently announced that on November 1, 2016, they will stop generating updates for Microsoft Exchange's "SmartScreen" spam filters used in Microsoft Exchange Server and the Outlook (Windows) desktop client. Read more about it here.

What does this mean? This is probably a good thing. These were primarily content-related filters and content filtering isn't really "where it's at" when it comes to best practices with regard to spam filtering nowadays. I believe that this ultimately will drive users to newer solutions that are probably going to be more focused on sending reputation, meaning that us deliverability and email technology-related folks will eventually no longer have to deal with Outlook desktop client spam folder issues, which were often a confusing outlier when reviewing email deliverability results.

Click here to read more on this topic, from Laura Atkins of Word to the Wise.

Deliverability Problems: What You Can't Fix


If you're having deliverability issues, I can tell you from my experience that you aren't really going to be able to get back to the inbox if any of the following types of subscriber list sources are in play: