Three Years of Email Automation Trends


Zack Zimmerman (aka ZZ aka TheZeez) is a valued team member here at Meldium. He’s our test account and in-house imaginary friend. Zack’s primary role is to test our integrations with over 2,000 popular SaaS products. After 3+ years, this email inbox – which has never sent out a single email – contains roughly 45,000 automated emails from SaaS products. With that much data, we couldn’t resist taking the time to do some analysis.

In this post, we decided to rank all the email services SaaS companies use. We will write more of these articles as we dig through the data set and would love to hear what you think we could uncover. Leave your suggestion for round 2 on Hacker News or in the comments here.

Round 1: What email services do SaaS companies use?

According to Wikipedia, there are two categories of marketing emails: transactional and direct marketing emails. A transactional email is an email sent to a specific user that is directly based off of an action that user made (eg. a password reset email). A direct email is an email sent to users that fall within certain qualifications (eg. an email sent to all free users with a coupon for the paid version). In the analysis below, we differentiate the services based on which of these types of emails they send.

We started the analysis by exporting Zack’s inbox as a .mbox file, which Google allows you to download. We then ran through the raw data using Python to look for sender domains recorded in each email’s Received header. If we found one or more servers mapping to a single service in the headers of an email, then the score for that service was incremented by one.

The Top 10:

Using this process, produced the following top 10 results:

Rank Name Percentage Transactional Marketing
1 SendGrid 15.7
2 MailChimp 13.2
3 Marketo 7.6
4 MailGun 7.3
5 Amazon SES 6.1
6 Mandrill 5.2
7 CreateSend 3.0
8 HubSpot 2.8
9 PostMark 1.9
10 Pardot 1.8

As seen in the table, SendGrid finished on top. According to our data, many email marketing services, including Hubspot and Pardot, are built on top of it which helps explain its high ranking. Mandrill as well is used as a base for marketing tools such as Marketo and Mailchimp.

We should note that this ranking involves some double counting where an email can be attributed to multiple senders. As we mentioned above, Hubspot is built off of SendGrid so mail sent with Hubspot is counted as both a Hubspot and a SendGrid email.