Email marketing continues to go from strength to strength but many companies are their own worst enemies, with aggressive marketing from brands – including LinkedIn, Uber One, McDonald’s, Gap, and Nintendo – now dominating unsubscribe and spam-flagging actions, rather than scammers.
According to the 2025–2026 Email Industry Data report from Clean Email, the global user base is set to reach 4.73 billion in 2026, up from 4.59 billion in 2025, with daily email volume projected to exceed 400 billion by 2027.
The key trends driving the industry include a 78% mobile open rate, the dominance of Apple Mail (over 50% market share), and a 4% annual growth in volume.
According to the report, open rates have finally found a “true engagement baseline”, stabilising at an average of 26.9% to 42.35%. While open rates are no longer the “North Star” for marketers, click-based metrics are on the rise.
Click-through rates (CTR) are projected to climb to 3.5% by 2026, signalling that while users may be more selective about what they open, they are more likely to take action once they do.
The report also highlights a “performance gap” between manual and automated campaigns. Automated email flows – which account for only 2% of total send volume –now drive a 41% of total email revenue. These automated “lifecycle” emails boast open rates of nearly 48.6%, nearly double the rate of standard manual blasts.
In addition, artificial intelligence has moved from an experimental tool to essential infrastructure, with 64% of marketers now using AI for content creation or send-time optimisation.
In fact, AI-optimised subject lines have seen a 50% higher open rate than traditional ones, while AI-driven personalisation is delivering a 41% increase in revenue for early adopters.
However, Clean Email’s “spam” analysis, which covered 10,292 randomly selected active users, approximately 200,000 emails for top senders alone, and up to 500,000 total emails, exposes the brutal truth that legitimate brands, not scammers, are the primary threat to inbox sanity.
The top ten companies whose emails users most frequently marked as spam reveal a who’s who of established brands. Tinder (which has 75 million users globally) has the dubious honour of leading the pack, followed by LinkedIn (1+ billion professionals); Uber One (171 million active users); McDonald’s (69 million app users); Zocdoc (6 million patients); Gap, La Poste-Colissimo (France); Shutterfly Customer Success and Nintendo.
The report states: “As we move into 2026, the data is clear: the most successful brands are those moving away from ‘batch-and-blast’ tactics in favour of behaviour-triggered, hyper-personalised experiences that respect the user’s increasingly crowded inbox.”
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