How many emails go unread every day?

Why email never died - it just grew into an unmanageable pile

~376.4 billion emails per day in 2025 (Radicati 2023-2027), growing ~4% per year to 392.5 billion/day in 2026. Most never get opened. Open rates for marketing: 20-40%. Spam, newsletters, alerts: often deleted unread. 35-45% of all emails go unopened — roughly 132-169 billion per day in 2025, or about 1.5 million unread emails every second.

What your unread email count is actually doing to your stress

The counter above tracks emails that piled up globally and were never opened. For many people, the unread count is personal: a survey by Adobe found the average professional spends 5.4 hours per day on email, yet a significant chunk of email - particularly newsletters and marketing - is never opened at all. The result is chronic inbox overload.

Researchers at UC Irvine found that workers who checked email less frequently experienced significantly lower stress levels and better focus. Every email notification is a potential context switch - and context switching has been measured to cost an average of 23 minutes to fully recover from. That means even a quick glance at an email that doesn't require action can cost nearly half an hour of deep work.

The uncomfortable truth: nobody ever "caught up" with email by spending more time on it. The volume always adapts to fill available attention. The only effective strategy researchers have identified is strict temporal batching - processing email at fixed times, not reactively, and ignoring the inbox between those times.

Email by the numbers: 376 billion sent, ~132 billion ignored (2025)

Email history: from ARPANET to inbox overload

1. 1971First email sent by Ray Tomlinson; "@" symbol established for email addresses
2. 1998Spam becomes a major problem; first anti-spam laws begin in various countries
3. 2010Radicati: ~247B emails/day; smartphone email access becomes mainstream
4. 2019293.6 billion emails/day; 3.9 billion users; Gmail dominant with 1.8B+ users
5. 2024361.6 billion emails/day; 4.48 billion users, ~56% of world population
6. 2025Radicati: 376.4 billion emails/day; 4.59 billion users; ~132 billion unread/day at 35% unread rate
7. 2026Radicati forecast: 392.5 billion emails/day; 4.73 billion users
8. 2027Radicati forecast: 408.2 billion emails/day; 4.85 billion users

Email volume growth: from millions to 376 billion per day (2025)

Email volume has grown from roughly 205 billion messages per day in 2015 to ~376 billion in 2025 (Radicati Group 2023-2027 forecast), and is tracked to reach ~392 billion/day by 2026. Average open rates have fallen from ~25% to under 20% over the same period, meaning the absolute number of unread emails climbs every year even as senders compete harder for attention.

Inside the unread pile: a significant share are phishing attacks waiting to be clicked

A significant fraction of unread email is phishing, malicious messages designed to steal credentials or money. Most are never opened, but enough are to make phishing a multi-billion dollar criminal industry.

The inbox overflow: why most email is never read

Research data

In perspective

How the number is calculated

Radicati Group Email Statistics Report 2023-2027: ~376.4 billion emails sent and received per day in 2025, rising to 392.5 billion/day in 2026 at ~4% CAGR. Applying a 35% never-opened rate (mid-range of published open-rate benchmarks, kept constant across datapoints for consistency): 376.4B × 35% = 131.7 billion unread/day ÷ 86,400 seconds = ~1,525,185 unread emails per second. The live counter uses this 2025 value; projected 2026 rate is ~1,590,000/sec.

Sources: Statista - Number of Emails Sent Worldwide per Day (archive, superseded by Radicati 2023-2027) - Radicati Group - Email Statistics Report 2023-2027 (daily traffic, users, forecasts). Methodology →

Frequently asked questions

How many emails are sent per day globally?

The Radicati Group's Email Statistics Report 2023-2027 puts worldwide email traffic at 376.4 billion messages sent and received per day in 2025, growing ~4.1% year-on-year to 392.5 billion/day in 2026 and 408.2 billion/day by 2027. The number of global email users rises from ~4.59 billion in 2025 to ~4.73 billion in 2026.

What percentage of emails are never opened?

Average email open rates across industries are 20-40%. Marketing emails average around 20-25% open rate. Factoring in spam (which is almost never opened), automated alerts, and newsletters, an estimated 35-45% of all emails are never opened — roughly 132-169 billion per day in 2025.

Is email still growing despite messaging apps?

Yes. Despite WhatsApp, Slack, Teams and other platforms, email continues to grow at ~4% per year. Email is uniquely entrenched in commerce, business correspondence, and authentication (every account needs an email address), ensuring continued growth. By 2027, over 4.85 billion people will use email (Radicati 2023-2027).