Email domains: One inbox is still stealing share from everyone else.

In 2013 we published our first email domain analysis. In 2015, we followed up on that analysis to look at what, if any, changes had occurred in the email provider landscape. Now, in 2019, we figured it was time to run the numbers one more time. Here’s what we found.

The Goods
To find our answer, we once again took a sample of golf resorts, ski resorts, and hotels. This sample included nearly 8,000,000 email addresses. We again focused on the core group of 5 domains and grouped the long tail into the “other” category.

To illustrate the changes in share for each domain, here’s a bar chart representing the change (in percentage points) for each one.

For our sample, Gmail now makes up more than 30% of all email addresses which is a nearly 10 percentage point or 47% increase versus 2015. Everything else dropped with AOL seeing the biggest change at -1.9 percentage points or -22%.

What This Means
Bottom line, Gmail continues to be the inbox marketers must account for. Whether it’s their efforts to reduce spam, tabbed inboxes, or annotations, HTML rendering quirks, or something not yet publicly available, Gmail matters.

And while we may not have a crystal ball, I see little reason for this trend to stop anytime soon.