The history of email marketing

Email marketing started with one unpopular message in 1978 and grew into an industry where single companies sell for billions. Here is how it happened, and every major email marketing service along the way.

Updated October 17, 2026 · 4 min read

1978: the first marketing email

On May 3, 1978, Gary Thuerk, a marketing manager at Digital Equipment Corporation, emailed an invitation to a product show to 393 people on ARPANET. Many recipients complained, but DEC credited the event with millions in sales. It is remembered as the first spam, and as proof that email could sell. The full story is in the history of email.

The 1980s and early 1990s: mailing lists

Before marketing tools existed, groups shared news through mailing-list software. LISTSERV, written by Eric Thomas in 1986, let one message reach everyone on a list automatically, and the word "listserv" still means a mailing list today. As the web opened to the public in the mid-1990s, businesses wanted the same thing for customers, and the first email service providers (ESPs) were born.

1995–2004: the first email marketing services

• Constant Contact (1995) started as Roving Software and became the go-to self-service tool for small businesses.
• AWeber (1998) popularized autoresponders, the automatic welcome and follow-up emails, and double opt-in, where people confirm they really want to join.
• GetResponse (1998) launched in Poland and grew into a global, affordable autoresponder service.
• CheetahMail and Responsys (1998), and Silverpop and Eloqua (1999), built tools for big brands sending millions of emails.
• ExactTarget (2000) grew into one of the largest enterprise platforms.
• Mailchimp, VerticalResponse and Infusionsoft (2001), Bronto (2002), ActiveCampaign and Emma (2003) and Campaign Monitor (2004) rounded out the first wave.

In the US, the CAN-SPAM Act of 2003 set the first national rules: no misleading subject lines, a real postal address, and a working unsubscribe link.

2006–2009: marketing automation and freemium

HubSpot (2006) popularized "inbound marketing" and tied email to a full CRM. Marketo (2006) and Pardot (2007) built automation for business-to-business sales teams, scoring leads by what they opened and clicked. Sailthru (2008) personalized email for big publishers in real time.

In 2009, Mailchimp introduced a free plan, which brought millions of small senders into email marketing and forced rivals to follow.

2009–2014: email for developers

Apps needed to send receipts, password resets and alerts, so a new kind of service appeared: email APIs. SendGrid (2009), Mailgun (2010), Mailchimp's Mandrill (2012) and SparkPost (2014) let developers send mail with a few lines of code. SendGrid later went public, and Twilio bought it in 2018. Amazon SES (January 2011) made very cheap sending available to any developer, and newer APIs such as Postmark and Resend (2023) compete on speed and simplicity. Mailgun bought Mailjet in 2019, and both became part of Sinch in 2021.

2010s: e-commerce and creators

Klaviyo (2012) connected email to online stores such as Shopify, so shops could email based on what each customer bought. It went public in 2023. Omnisend (2014), Drip (2012) and Maropost (2011) also focused on online sellers.

For individuals, ConvertKit (2013, now Kit) served bloggers and creators, while MailerLite (2010) and Sendinblue (2012, now Brevo) won customers with simple tools and low prices.

The 2020s: the newsletter boom

Substack (2017) let writers charge for newsletters and kept the email address list theirs, and beehiiv (2021) followed with growth and ad tools. Independent writers, local news and creators turned email back into a direct, paid relationship with readers, with no social media algorithm in between.

The billion-dollar deals

Other notable deals: Experian bought CheetahMail (2004), Salesforce's ExactTarget bought Pardot (2012), IBM bought Silverpop (2014), GoDaddy bought Mad Mimi (2014), and Aurea bought Lyris (2015). Campaign Monitor, Emma, Sailthru and Cheetah Digital later joined together under the name Marigold.

Rules and privacy: 2003 to today

• 2003: CAN-SPAM in the US.
• 2014: Canada's anti-spam law (CASL) takes effect, requiring permission before you email.
• 2018: Europe's GDPR tightens consent and data rules.
• 2021: Apple's Mail Privacy Protection makes "open rates" unreliable by loading images automatically.
• 2024–2025: Gmail and Yahoo (February 2024) and Microsoft (2025) require bulk senders to use SPF, DKIM and DMARC, offer one-click unsubscribe, and keep spam complaints very low.

The common thread: inbox providers reward senders with clean, permission-based lists. Before any campaign, clean your list and check your domain with the free DMARC and SPF checker.

Every major email marketing service, at a glance

Questions people ask

When did email marketing start?

The first marketing email was sent on May 3, 1978, by Gary Thuerk of Digital Equipment Corporation, to 393 ARPANET users.

What was the first email marketing service?

Constant Contact, founded in 1995 as Roving Software, is one of the earliest self-service email marketing services still running.

When was Mailchimp founded?

Mailchimp was founded in 2001, added a free plan in 2009, and was bought by Intuit for about $12 billion in 2021.

What is an ESP?

An email service provider: a company that sends marketing or transactional email for you, handling lists, unsubscribes and delivery.