Email Marketing History · 1971 to AI Personalisation 2026

Ray Tomlinson sent the first networked email in 1971 using ARPANET — the precursor to the internet — sending a message between two computers in the same room using the @ symbol to separate the user name from the host machine. His choice of @ established the convention that persists in every email address today.

The first email sent for marketing purposes is generally attributed to Gary Thuerk, a Digital Equipment Corporation marketing manager who sent an unsolicited promotional email to 400 ARPANET users in 1978 — advertising DEC computers. The message generated significant complaints from recipients unused to commercial messages in a network they considered academic and professional. Thuerk has since been called "the father of spam" — though his email was more accurately the first bulk commercial email, predating the modern spam phenomenon by two decades.

The commercialisation of the internet in the early 1990s brought email to the mainstream. Hotmail (1996) and Yahoo Mail (1997) made free web-based email accessible to millions of non-technical users. By the late 1990s, marketing departments at major corporations were building email lists and sending HTML-formatted promotional emails to hundreds of thousands of subscribers.

By 2001, unsolicited commercial email — spam — represented over 50% of all email traffic. The dotcom crash had left thousands of failed companies with large email lists and no ethical constraints on how to monetise them. Spam volumes accelerated throughout 2002–2004, with some estimates placing spam at 80–85% of global email traffic by 2004.

The spam crisis had two lasting consequences for legitimate email marketers: inbox placement became difficult even for permission-based senders (ISPs deployed aggressive filtering that caught legitimate email alongside spam), and users' trust in commercial email collapsed — causing open rates across the industry to fall sharply.

The US CAN-SPAM Act (Controlling the Assault of Non-Solicited Pornography And Marketing Act) was signed into law on December 16, 2003, establishing the first federal standards for commercial email in the United States. CAN-SPAM set requirements for commercial email: accurate header information, clear identification as an advertisement, physical postal address, and a functional opt-out mechanism honoured within 10 business days.

The introduction of smartphones — particularly the iPhone (2007) and Android (2008) — fundamentally changed how people read email. By 2013, mobile surpassed desktop as the dominant email reading environment for the first time. Email designs built for 600px-wide desktop clients were unreadable on mobile screens — forcing the industry to develop responsive email design.

Marketing automation platforms — Mailchimp, Klaviyo, HubSpot, ActiveCampaign, Salesforce Marketing Cloud — matured during this period, making sophisticated trigger-based email sequences accessible to businesses of all sizes. Behavioural triggers (abandoned cart, browse abandonment, post-purchase), lifecycle automation (welcome series, win-back sequences), and predictive send-time optimisation became standard capabilities.

AI and machine learning have progressively entered email marketing at multiple levels: generative AI for subject line and body copy creation; predictive analytics for churn risk and purchase probability; dynamic content personalisation at the individual level; and send-time optimisation that determines the optimal send moment per subscriber based on historical engagement patterns.

Authentic Sources