Interactive email: AMP, embedded forms and micro-conversions

In brief: An interactive email lets the recipient reply, rate or choose without leaving their inbox. AMP for Email makes that possible in Gmail and Yahoo, but not in Outlook or Apple Mail. In B2B, the fallback version is therefore still the piece that matters most.

What is an interactive email?

A conventional email really offers only one action: the click. The recipient reads, clicks a link, and everything that matters then happens on a web page. An interactive email brings part of that action back into the message itself. Answering a question, rating a service, scrolling through images, expanding a section, picking a time slot. All without opening a browser.

There is nothing new about the idea. For more than ten years, email developers have been cobbling together carousels and drop-down menus in pure CSS, with results that vary from one email client to the next. What changed was the arrival in 2019 of a format designed for the job, AMP for Email, and with it the ability to send data from a message and then get some back.

The word “interactive” actually covers three techniques that have very little to do with one another. Mixing them up accounts for a good share of the disappointment.

AMP for Email, the standard championed by Google

An email normally goes out with two versions of the same content, plain text and HTML. AMP for Email slips in a third, declared under the text/x-amp-html type. An email client that can read it displays it. The rest ignore it and fall back on the HTML, without the recipient noticing a thing. The specification published on amp.dev in fact recommends placing this part before the HTML, since some clients only read the last one.

What the format allows

No free-form JavaScript: that is the ground rule. The sender works from a closed library of components: amp-form for forms, amp-carousel for slideshows, amp-accordion for collapsible blocks, amp-selector for choices, amp-list for loading up-to-date content at the moment of opening. The markup must not exceed 200,000 bytes and the style sheet 50,000, again according to the specification.

The constraint is deliberate. It assures the email client that a message cannot run anything unexpected, and that is what made the format acceptable to Gmail.

Registration first, one address at a time

You cannot start sending AMP overnight. Google asks every sender to register: you have to send it a genuine production email, AMP part included, then fill in a form. The Gmail documentation says most requests get an answer within five working days. And approval covers one sender address, not a whole domain.

The technical requirements are those of a clean sending setup. SPF, DKIM and DMARC in place, a DKIM signature aligned with the domain of the sending address, TLS encryption in transit. Yahoo runs its own procedure, on the same principle. If just one of these rules is not met, Gmail shows the HTML version, without telling anyone.

Content that does not last

Two behaviours often catch people out. When the recipient replies to the message or forwards it to a colleague, the email client strips out the AMP part: the colleague gets the HTML version. And the specification allows a client to stop displaying the interactive part after a certain period, with thirty days given as an example. An AMP email dug out of an inbox two months later has therefore, in all likelihood, gone back to being an ordinary email.

The interactive elements available

Four families cover most uses.

• The form. One or two fields, a button, and the answer is sent without leaving the inbox. The message then shows a confirmation in place of the form.
• The carousel. Several images in the same slot, which the reader scrolls through. Handy for presenting a range or the steps of a demonstration without making the message any longer.
• The accordion. Collapsed sections that open with a click. A dense newsletter gains a great deal from it, especially on mobile.
• The rating. A row of stars or a scale from 0 to 10, for a satisfaction survey that takes a single tap.

Then there is refreshed content. With AMP, a block can fetch its data at the moment of opening: the places left at an event, the status of an order, the list of slots still free.

What CSS can do without AMP

Carousels and accordions existed before AMP. The technique relies on invisible checkboxes and the :checked CSS selector, or on simple hover effects. It sends no data; all it does is show or hide blocks already present in the message.

Its weakness is compatibility. According to the support data compiled by caniemail.com, the industry reference on these questions, :checked works in Apple Mail but in neither Gmail nor the Windows versions of Outlook. Every component therefore needs a fallback, and a lot of testing.

The standard HTML form, tempting but unreliable

Dropping a <form> tag into an email looks simpler. In practice, support is too uneven to rely on. Some email clients display the form without passing on the values, others disable it, and others again do not allow it in the reading pane. The most recent tests caniemail has published on this point date from 2019 and put support at roughly half of the email clients in use. A form that displays and sends nothing is the worst case of all: the recipient believes they have answered.

Compatibility by email client

For a B2B sender, this is where everything is decided.

Sources: the list of supported clients maintained by amp.dev and the support data compiled by caniemail.com.

Outlook deserves a word. Microsoft had opened a developer-only preview of AMP on Outlook.com, then closed it in the autumn of 2020. Plenty of articles still announce that support in the future tense. It does not exist.

Yet a large share of French business mailboxes run on Microsoft 365, and Apple Mail leads the opens that Litmus measures in its monthly email client figures. On a B2B list, the interactive version will therefore reach only a minority of your contacts, those who read their email in Gmail or Google Workspace. Everyone else will see the fallback. Better to know that before costing the project.

Practical B2B use cases and micro-conversions

A micro-conversion is a small, measurable step towards the end goal: a reply, a choice, a sign-up. Interactive email is its natural home, since it removes the stage where most people drop out, the move from the message to the web page. A few scenarios that make sense in B2B:

• Signing up for a webinar or a trade show in one click, with the confirmation shown in the message and the number of places left kept up to date.
• The satisfaction survey after a support ticket is closed or a project is delivered. A score, an optional comment, nothing more.
• Qualifying a lead who is already in touch with your company. A single question, for example the timescale of their project, whose answer feeds your scoring.
• Choosing subscription preferences: topics, frequency, without going through an external preference centre.
• Booking an appointment from slots that are really available at the moment the contact opens the email.

All these examples have one thing in common: they are aimed at contacts who already know who you are. For cold prospecting, interactive email is the wrong vehicle. Registration presupposes an established sender reputation, and a first message loaded with dynamic components rarely reassures a stranger.

On effectiveness, some caution is in order. The spectacular jumps in response rates doing the rounds come from customer case studies published by the AMP solution vendors themselves. To our knowledge, no independent study confirms them. The only figure worth having will be your own, measured on your own list.

Limits and precautions

Three versions to build and test

An AMP email is one email in three copies: the text, the HTML, the interactive version. Each must carry the same message and stand on its own. Build and testing time goes up in proportion, and it has to be weighed against the number of contacts who will really see the interactivity.

The HTML version therefore deserves the greatest care, since it is the one most of your recipients will read. It is built like any other campaign, in a tool that guarantees it renders properly in Outlook as well as on mobile. That is the job of the Ediware email editor. The right habit is to design this fallback first, with a button that leads to a web page, and only then ask what interactivity would add.

Measurement needs a rethink

The AMP format does not accept the usual web measurement components. Interactions are counted server-side, at the endpoint that receives the form responses. Your dashboards will need to separate what belongs to the interactive version from what belongs to the ordinary click, or you will end up comparing things that cannot be compared.

Personal data like any other

An answer typed into an email is still personal data collected through a form. The information that the CNIL, the French data protection authority, expects on any form applies: the identity of the data controller, the purpose, the legal basis, the retention period, the individual’s rights and how to exercise them. In a message, space is short. A link to the privacy policy just below the button, and fields cut down to the bare minimum, take care of the essentials.

Start with one question, one click

Before investing in AMP, there is one form of interactivity that works everywhere, Outlook included. Ask a single question in your email and offer each answer as a link or a button. Each link points to a page that records the choice and says thank you. Technically, it is a tracked click. For the recipient, it is an answer given in a second. And you get a measurable micro-conversion across your entire list.

If this first trial produces answers you can use, you will know that interactivity appeals to your contacts, and the share of them reading in Gmail will tell you whether AMP is worth the development work. If not, you will have saved several weeks of build time.

One last reminder, which holds for every technique described here: an interactive email that nobody opens converts nothing. Before working on the content, take the time to focus on getting your subject line right. It is the subject line that decides whether your form stands a chance of being seen.