SupportHTML email requirements

HTML email requirements

December 2025

As well as offering a visual drag-and-drop builder, EcoSend supports sending emails that have been crafted with HTML.

It's important to note a few requirements when creating an email with HTML in EcoSend — most notably, ensuring you have an unsubscribe link in every email you send.

Unsubscribe Link

Every email must contain an unsubscribe link, giving the recipient control over emails they receive.

EcoSend will not allow you to send a campaign without having a valid unsubscribe link in the the email content.

To add an unsubscribe link to your HTML emails, include the following in your HTML content:

<a href="{{unsubscribe_url}}">Unsubscribe</a>

Ensure you update the plaintext version of your email too, with:

Unsubscribe: {{unsubscribe_url}}

{{unsubscribe_url}} will automatically get converted to the correct URL when the email is sent.

Ready to grow with purpose?

Start sending smarter campaigns that build your brand and the planet.

Designed for mission-led brands • Good for your growth and your impact • Risk-free to try

👉 Get Started Free