A word on SSL/TLS and on competitive intelligence using Google’s transparency report data

HTTPS encryption is hot in the news for some time, now. It not only affects online marketing on webpages, but also email marketing practices. Google shares open data that sheds light on the adoption of email encryption. I present you a view on the data set from a completely different perspective.

HTTPS beeing hot these days

HTTPS wants to make connections between browsers and websites safer using SSL or TLS encryption. For instance, no man-in-the-middle like the NSA should be able to intercept an email address, which was submitted in a newsletter sign-up form.

Email messages themselves shouldn’t be an exception. For example, it’s recommended to reference images like your open tracking pixel via HTTPS instead of HTTP in order to prevent unexpected surprises that could harm campaign outcomes. Even more importantly, any submission and transmission should be based on HTTPS and TLS protected SMTP connections. Otherwise transportation would be just like passing postcards over the web. Many were not aware of that, at least until the NSA knocked on several doors, undermining trust and conficence in the web.

Back in 2013, email service providers in Germany sort of newsjacked the NSA data surveillance scandals. GMX, WEB.DE, T-Online and a few others formed an alliance called e-mail-made-in-germany.de to build a “safe harbor”, with which they want to ensure safe email transportation among themselves. The participants covers about 70% of the market of primary consumer email addresses in Germany. Although I doubt that the alliance around data privacy contributed significantly to that. Anyway.

Pushing SSL/TLS adoption forward

All the big internet companies thematise and push HTTPS these days. Facebook analyzed the current state of SMTP STARTTLS deployment a while ago. Gmail’s Postmaster Tools report the encryption rate back to senders:

Gmail Postmaster Tools show TLS encryption percentageGmail also marks those messages, which have not been transmitted over a secure connection, with a red warning signet:

Non-TLS encrypted emails are marked with a red signThus, if you don’t want to irritate your Gmail subscribers, make sure your mailservers submit messages securely using TLS encryption.

Google itself maintains the Transparency Report, which holds data about HTTPS encryption on the web and also on email encryption in transit. You can download the email data set as a (zipped) CSV file at the bottom of the page, where it says “Let’s make email safer”. It’s about sixty thousand rows and looks like this:

Google transparency report data set

Google data for competitive intelligence?

The data set holds more than meets the eye. To me, the most interesting part is not necessarily the percentage of TLS inbound and outbound traffic from different domains. It lies in email service provider (ESP) popularity and ESP usage trends, which you can derive from it – to a certain degree. I wrote about it already in this post.

Now, more than one year later, let’s have another look on what changed: Who might use – according to Google’s data – a different provider today than compared to a year ago? Which ESPs gained the most from migrations?

Email Service Provider popularity year-on-year

Here’s an excerpt on ESP migration data. Hover over the sankey chart links to get more info about which domains migrated – according to the data – from the source ESP (left) to the target one (right):

Of course such insights have got to be enjoyed with caution. For example, the link from optivo to artegic says “payback.de”. However, the domain payback.de just uses both ESPs as far as I know – there was no provider reconsideration. In addition, many domains could not be assigned a year ago (“?”) and also this year, which may distort the picture. The same goes for Google choosing which domains to report:

Update 2019-01-13:

The following two charts compare data from 2019-01-13 and 2017-10-27:

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One Response to A word on SSL/TLS and on competitive intelligence using Google’s transparency report data

  1. stephen pazyra

    Interesting, My outbound tls is always N/A. We use mailchimp. Is this a problem you think. We have problems with gmail even though we have done everything it asks. ~ Steve

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