That’s right. Two years already! Two years since I wrote this article on the Badsender blog. Since then, a lot of work has been done, but as we knew when we started, it takes a long time. To paraphrase Benjamin (who manages the technical aspects of the project), it’s clearly more of a marathon than a sprint.

(If at the time of reading this article you don’t yet know the basics of the project, feel free to read up on it here:

A lot of time, because our objective is both: to change elements of culture and technology.

Culture, because in the digital world, we have the feeling that the playground is unlimited. That we can break free from physical limitations. Culture, because in the business world, we rarely work without financial objectives. But this project does not make money. It even costs time. Getting involved to act on the climate emergency requires the involvement of everyone and a change of mindset. A change of mindset for advertisers (and therefore campaign managers), email service providers, mailbox providers and end-users.

Technology, because email is an old lady that you don’t want to shake up. Changing the fundamentals of email (in this case the SMTP protocol) takes time. It takes time because the change requires the approval of a community of experts. Takes time because to be adopted, a new technology must be proven. Although clearly, with expiry dates we are more into low tech than high tech.

A lot of ground has been covered

120+ business supporters

In two years, more than 120 companies have given us their support. Advertisers, mailbox providers, marketing platforms and agencies.

Obviously, among these companies, the level of involvement in the project is more or less great, but from the beginning we felt that there was an interest. We felt that this initiative responded to a real need to find concrete solutions to the climate emergency.

So obviously, email is only a small part of digital carbon emissions, which are themselves a small part of global carbon emissions. But the effort must come from every sector. So let’s do our bit.

Check out Badsender’s guide to the role of CRM teams in the green transition.

A draft standard published at the IETF

An RFC (for Request For Comment) is the basis for any technological standard on the Internet. With the help of a few volunteers, Benjamin Billon took the most technical part of our initiative to the IETF (the Internet Engineering Task Force, which develops and promotes Internet standards).

For the initiated, you can find this work here:

This means that as of now, even in draft stage, the expiration date project has sufficient legitimacy to be implemented in email solutions and messaging systems.

However, even when the standard is finally validated, the functionality will not necessarily be implemented immediately. Mailbox providers need proof that the header is actually used. This is what Yahoo! told Benjamin, for example, and we know that French operators (Orange, SFR, La Poste) are also interested but are waiting to see the sector move.

An analysis of use cases by advertisers

Since June 2022, several advertisers from different sectors of activity have met in 3 workshops to work on the use cases of the expiry date concerning them.

The objective was to list all the types of emails that are sent by brands and to think about how to use expiration dates. Despite a great diversity in the typologies of emails, the working group managed to identify 3 types of values for the date:

  • Dynamic values based on the send date (send date + x days).
  • A date calculated according to a parameter (e.g. the validity date of an offer).
  • A fixed date defined at the time of sending by the campaign manager.

The conclusion of the working group is that after 90 days, apart from a few exceptions, there are almost no emails that remain current. So a big effect for very little effort, since adding the date is simply adding a parameter with the same title as a subject or a sending date.

However, care must be taken with these exceptions: sending invoices, updating contractual conditions, etc.

The next step for the advertisers’ working group is to extend the group to other sectors of activity in order to confirm these assumptions. All these elements will then have to be documented on the project website.

First ESPs that allow the use of expiry date

Over the last few months, we have been able to confirm that some routers are already capable of sending emails with the new standard expiration date. This is the case for example with Adobe Campaign, Splio and Numergy, which make it easy to add an SMTP header to emails. A test was successfully carried out by the SNCF (French railways).

Should funds be raised to accelerate the project?

All these advances are remarkable! But in this ambitious project (you remember, changing culture and technology 😉 ) it is not always easy to move forward quickly. Everyone gives time, privately or on behalf of their company, and this type of project is rarely the number one priority.

This is why the question arises today! Do we need to raise money to speed up the project?

What would be the use of these resources?

Having a project coordinator

Having a person dedicated to the project seems to us at this stage essential to make it progress. Probably a person available half-time.

This person could use his/her time to :

  • coordinate all the next steps (see below)
  • communicate better on the project, particularly on the website
  • be more reactive when there are questions from the community
  • update the benchmark for using the expiration date (see below)
  • welcome new supporters in good conditions in order to explain to them what they can help with
  • … and generally anything else we can’t do at the moment.

Ask for an independent study on the impacts of the initiative

There are still many questions about the positive impact that an expiration date based email cleaning mechanism could have. The main point is that the action of deleting an email would be more consuming than leaving the email in storage.

This is a point (among others) that deserves attention. To do this, we need to analyse the energy consumption and carbon emissions of the entire life cycle of email storage. From the manufacture of the storage space to its recycling and operation in the data centres.

A full brief should therefore be developed and submitted to a recognised independent expert on both the energy consumption of the digital world and on digital carbon emissions. A study that will inevitably cost money.

Give your opinion! Does the project need to raise money?

Yes, of course! To pay the project coordinator and to finance the study on the impact of the project by an independent expert.

How much?

We estimate the need at about 30,000 euros per year (10,000 euros for the study and 40 hours/month for project coordination).

By whom?

By corporate sponsors with Platinum, Gold and Silver status.


We prefer to avoid setting up an association because this solution seems to us to be very time-consuming due to its administrative burden.

So would you agree to entrust the administration of the budget to Badsender? Badsender would manage the funds, pay the coordinator and the study, and more if needed, but always in the most transparent way. In order to guarantee the greatest transparency, we will set up a strict framework, a separate account, dedicated accounting and an annual report.

What do you think?

What are the next steps? On which topics should we help?

Below you will find a list of topics on which we now need to move forward:

  • Create a benchmark: in order to encourage the use of expiration dates by advertisers, to prove to the industry that the movement is underway, we propose to create a benchmark. This will allow us to publish the evolution of the number of emails sent with the expiration header every month.
  • Conduct an independent study: see above
  • Document the use of the header in solutions that allow it: this will start with Adobe Campaign, but potentially many other solutions may already be involved.
  • Publish the results of the Sender Working Group’s work on our website: to give more visibility to this work and to encourage other companies to contribute.
  • Establish an ESP (email service provider) working group: to document ways of implementing the expiration date in email campaign management solutions.
  • Establish a Mailbox Providers working group: to document ways to implement expiration dates in email solutions.
  • Establish a legal working group: to reflect on the impact of national legislation and propose ways for Mailbox Providers to modify their general conditions.

Please feel free to take up this list and offer to help: