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Mailsweeper will automatically clean up unimportant emails to reduce your digital carbon footprint.

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Numbers tell the story

The number of emails is growing daily. Some of these are spam, and (hopefully) caught by spam filters. But some are emails that we might read once, or the information is only value for a short period of time. These emails are often forgotten about, and left to sit in our inboxes, taking up space and energy or time.

The average carbon cost of an email is around 0.3g. However, longer email or adding attachments ups the ante significantly, with emissions as high as 50g. The bulk of this carbon footprint comes from the manufacturing and powering of our devices, plus the energy used by networks and data centers to keep our digital conversations alive. Though each email might seem minor, with billions of users worldwide, it all adds up to a significant environmental impact.Berners-Lee estimates that emails could account for as much as 150m tonnes CO2e in 2019, or about 0.3% of the world’s carbon footprint.


of CO2 for an average email


emails average received per day, per person


Billion users of email worldwide.

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Calculated Carbon Reduction

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Other useful metrics around your emails deleted and storage space saved.

Frequently Asked questions

The Cost of Email

1. How does email create carbon emissions?

Every email you’ve got is stored in a data center. These contain computers that work non-stop, guzzling energy and needing tons of water or air conditioning to stay cool.

2. Do spam filters help?

Of course. But spam filters don’t handle emails that you might read once, or the information is only valuable for a short period of time (promotions).

3. Aren’t data centers powered by renewables?

Not completely. And even when they are, there is always an opportunity cost: if these servers didn’t need power to store my email, where else would we use this energy.

4. What more could be done?

The easiest thing for now is just to delete unimportant emails. This is why we built Mail Sweeper. We hope you like it as much as we do.