Gmail’s promotional email annotations – a new opportunity for senders

Six years since Gmail introduced its tabbed inbox, it now aims to bring the most relevant promotional emails to users’ attention. Email developer Steve Hart goes into the technical details in this guide.

With tabs, Gmail sought to bring order to the inbox. Using sophisticated machine learning, this feature automatically organises a user’s personal and promotional inbound emails into categories. But the move was largely unpopular with bulk senders because of concerns that promotional and marketing emails could be unnecessarily penalised – potentially going unseen in the ‘Promotions’ tab of the customer’s inbox.Fast forward to 2019 and with a new vision for its Promotions inbox, Gmail presents its promotional email annotations. With this update and the co-operation of bulk senders, Gmail hopes to improve user experience. Unlike the tabbed inbox, it’s been pitched to bulk senders as an opportunity to increase the visibility of their promotional emails.

What’s the update?

Senders will now be able to highlight the key contents of their offer, before the promotional email is even opened. This includes highlighting the type of offer (such as % discount), discount codes and deal expiration period. There’s even the opportunity to show a brand logo and a larger banner-sized product image, which Gmail is referring to as the ‘promotion card image’. Senders can do this by using embedded Gmail-recognised code (JSON-LD or microdata formats) within the HTML format of the email – a practise it calls ‘annotating’. The highlights are presented next to the usual sender name and subject information of the email.

As you can probably guess at this point, this goes some way beyond the usual text-based sender name, subject and preview that usually greets and entices the recipient to open it. This highlight feature only kicks in for inbound emails within the Promotions tab of the Gmail inbox. Inbound emails to other tabs, such as the Primary or Social tab, will not get the highlight treatment.

Another change taking place within the Promotions tab is in the conventional date-ordered list view of received emails. Gmail will begin determining the most relevant promotional emails to the user in the moment, and group and display these at the top of the tab. This practise is called ‘bundling’, with emails appearing in bundles grouped under thematically similar headings . For now, these are generic titles such as ‘top deals’ or ‘top offers’, but based on early previews Gmail plans to add ‘shopping’, ‘entertainment’ and others to the mix.  All change for the Promotions tab. How annotated emails can look in the Promotions inbox. Image courtesy of Google.

Gmail-annotated-email with promoted key content


The finer details

Gmail has confirmed that even if an email is not annotated it can still appear in a bundle. In this scenario, Gmail can’t show the highlights of the email within the bundle.

While annotating makes the email appear more prominently, if an expiration period is specified the email can appear more than once in a bundle during that time, increasing its exposure within the inbox. The matter of which emails receive the bundling and highlighting treatment is determined by Gmail’s machine learning. And while the exact details of this are not publicly available, Gmail has indicated that the algorithm considers sender reputation, email content and the user’s previous behaviour and relationship with those brands’ emails. Because of this, bulk senders can’t be sure their emails will always feature in a bundle or be highlighted.

The feature, which is already available in the Gmail application for Android and iOS, looks set to be rolled-out to its webmail environment later this year.

Best practice points

Gmail has published some much-welcomed official documentation for marketers and developers.

But now I’ll share some best practice tips and answers to frequently asked questions, which I’ve compiled from Gmail’s guidance and my own testing and research:

Logo image

  • Serve the image via HTTPS
  • It is auto-resized to fit in a squared area
  • It is auto-cropped circular

Deal badge

  • Use this to highlight the offer, don’t repurpose this field for something else
  • Avoid repeating information from the subject line
  • Keep it short

Discount code

  • Only use if there is a discount code; do not repurpose this field for anything else

Expiration date

  • Specify a start and/or end date to the deal if there is one
  • Ensure the appropriate time zone to the offer is specified

Promotion card image

  • Use a representative image
  • Refresh the image for each email
  • Gmail automatically crops the image to a 3.9:1 aspect ratio from centre. Prepare the image accordingly
  • GIF or WEBP image formats are unsupported.

Frequently asked questions

  • So, is this worth implementing only for Gmail? 

    Consider that Gmail is one of the major mailbox providers. Barriers to set this up are low; Gmail has deliberately made this simple to implement to encourage take-up. It is therefore likely that brands will be making use of this as soon as possible.

  • Is it trackable? Can we track impressions or opens from recipients clicking on Gmail bundled highlighted emails? 

    Gmail is not making the bundling or highlighting reportable.

  • What about emails which are not deal or discount based – is annotation unsuitable for those emails? 

    Gmail have said that emails not featuring deals can still be annotated. For example, that might include specifying a logo.

  • If an email isn’t annotated, will it still appear in a bundle within the Promotions tab? 

    Yes, emails that have not been annotated can still potentially appear in a bundle.

  • Will including annotation within the email affect the email’s inbox category placement in Gmail’s tabbed inbox? 

    Gmail has allayed concerns by confirming that including the annotation code within an email will not affect its placement in the tabbed inbox.

  • Can we guarantee each time an annotated email is sent that it will be shown in a bundle and highlighted in Gmail to the recipient? 

    There is no such guarantee. Gmail’s machine learning controls this.

  • How can the annotation be validated? 

    Google has provided a handy tool for this here.

  • Might the annotation code affect email deliverability with other mailbox providers? 

    This is an unknown. The advice is to monitor deliverability closely for any annotated email. One thing to note is that many brands are already paving the way in using this.

Some final thoughts

Gmail has intentionally made email annotation simple to implement in emails. So it’s likely we’ll see quick adoption by bulk senders. Gmail is asking bulk senders to provide specific information about their emails for further versatility inside its inbox environment, and similar ideas were present in the Inbox by Gmail project (which Google has announced it will shut down in March 2019). The focus will now be firmly on Gmail and it is likely to introduce more features based on this annotation practice.

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Steve Hart

email developer, Profusion


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