CATEGORY: Environmental impact of an email

Environmental impact of an email

Environmental impact of an email

How email affects the use of Carbon

The carbon footprint of an email comes from the electricity that is used to power the devices on which it is written and read, the networks that transmit the data, and the data centres that store it. 

Experts estimate data centres account for less than 0.1 per cent of the world's carbon footprint, a small figure compared with the 20 per cent blamed on cars. However, emissions from data centres are growing because of increased use of online media such as video calls, games, and streaming.

One piece of open source information referred to by officials relates to research commissioned by Ovo Energy November 2020, which suggested that if each person in the UK sent one fewer email a day it could cut carbon output by more than 16,400 tonnes a year.

Calculating the emissions generated by an email is no easy task. It depends on the device used to create the email, whether it is the latest phone or an old desktop computer. You then must factor in how long it took for the sender to write it and the reader to read it. Did the sender add pictures, attach a big document, or sign off with a signature including the company logo? Then there is the energy used to send it and how efficient the various data centres are through which it passes. All these things have an impact. So, the best way to estimate is to look at a range.

In the latest version of his book, ‘How Bad are Bananas?: The Carbon Footprint of Everything’ (2020), Mike Berners-Lee puts that range at between 0.03g and 26g. That is less than the estimates in his earlier work – partly because devices and data centres are becoming more efficient.

At the low end are spam emails that have been picked up by spam filters and never even make it to the inbox. Statistical, it’s estimated to be approximately half of all the emails that are ever sent. At the other end are mailings that take a long time to write, and are sent inefficiently by systems that are not dedicated


  • Spam email picked up by spam filters - 0.03 g (CO2e)

  • Short email sent and received on a phone - 0.2 g (CO2e)

  • Short email sent and received on a laptop - 0.3 g (CO2e)

  • Long email that takes 10 minutes to write and 3 minutes to read sent and received on a laptop - 17 g (CO2e)

  • Email created on the e-shot platform that takes 10 minutes to write and bulk sent to 100,000 people in less than 1 minute - 15 g (CO2e)

  • Email created on Desktop Outlook that takes 10 minutes to write and sent individually to 100 people - 26 g (CO2e)


How using e-shot™ helps save carbon

Using e-shot reduces the impact and carbon footprint compared to sending a direct email for the following reasons:

  • e-shot infrastructure was migrated in 2018 to one of the UK’s most energy efficient data centres, which uses 100% carbon neutral, renewable energy provided from UK wind farms.

  • All equipment and infrastructure used is the latest eco-friendly, energy efficient new generation servers of the highest energy efficiency rating possible.

  • The energy efficiency of the data centre equipment is regularly measured for efficiency and is regularly updated.

  • Using an efficient ‘built for purpose’ system to deliver very high volume of emails is much more efficient than creating individual direct emails or using mail-merge technology.

  • E-shot manages engagement and response which effectively reduces the number of emails sent by excluding unsubscribes and hard bounces automatically.

  • Using predefined campaign templates saves considerable time to create pre-approved engaging campaigns with consistent branding.

  • Creating campaigns using existing designs further saves on time and reduce computing power.

  • Automatic management of subscription with sign up pages considerably reduces computing time spent on producing contact lists.

  • Managing Preference centre that enables subscribers to choose and control their interests not only resolves data protection issues but is proven to impact engagement and reduce wastage which results in fewer emails being sent.

  • Some organisations are now promoting ‘accept my thank you’ to prevent unnecessary replies. E-shot can use a no-reply from address which prevents replies automatically.

  • Forfront commitment to reducing carbon footprint as an organisation is reflected in the development of e-shot, its functionality and infrastructure to provide a better environment.

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