Gmail Annotations: boost your promos before the click

Your email hasn't even been opened, and the recipient can already see the price, the discount, and the product photo. That's what Gmail Email Annotations do.

Available in the Promotions tab of the Gmail mobile app, annotations let you surface a product carousel or a promotional badge directly in the inbox. No click required. The recipient sees the value of your offer before they even decide to open the email, which is exactly why annotated campaigns tend to see stronger visibility and engagement.

Here's what annotations look like, how to set them up in Batch, and what to expect once they're live.

Two formats, two use cases

Batch supports two types of Gmail annotations.

Product carousels display up to 10 items, each with its own image, description, and price. Perfect for a catalog push or a seasonal collection.

Deal annotations show a single promotional badge next to your subject line, with a discount code, a short offer description, and the validity window. Ideal for flash sales or time-limited offers.

Both formats are configured directly from the Batch email composer.

Before you can use them: Google's allowlist

Annotations aren’t a toggle you flip and forget. Google reviews every brand before allowing its emails to carry annotations.

To apply, you need to send Google:

• Your brand information (name, website, etc.)

• The subdomains you use to send emails with annotations

• The link-tracking subdomain used in your emails (e.g. click.yourdomain.com)

Send this information to p-Promo-Outreach@google.com. Review typically takes 5 to 10 business days, sometimes longer, so plan ahead of your campaign launch.

Setting up a template in Batch

Once your brand is allowlisted, setup takes minutes.

Open your template's global settings from the Batch email composer and enable Email Annotations for Gmail. From there, choose your annotation type, configure it, and preview the result before sending.

For a product carousel, you'll set:

• A sender logo (minimum 40×40 px, PNG, JPG, or GIF)

• Whether to display a headline and price under each item

• For each product: an image (PNG or JPEG, same aspect ratio across all items: 4:5, 1:1, or 1.91:1), a destination URL, a 1-2 line headline, a currency and price, and an optional discount

Set a discount and Batch does the math for you. Enter 10 on a €100 item, and the carousel shows €90 automatically.

For a deal annotation, you'll set:

• A sender logo

• A short deal description (e.g. "Free delivery")

• A discount code

• The offer's start and end time

Will your annotation actually show up?

This is where most questions come in. Google controls annotation display, and five conditions must all be met at once:

1. It's a mass send. The same email needs to go to more than 100 recipients, with identical content and image URLs across every recipient. One-off sends and test campaigns won’t trigger annotations, ever.

2. Your sender domain is allowlisted. No approval, no annotation.

3. The recipient opens the email in the Gmail mobile app. Desktop and mobile web don’t support annotations.

4. The email lands in the Promotions tab. Primary inbox and other tabs never show annotations.

5. The inbox isn't already saturated. Google caps how many annotated emails can appear at once. If a recipient’s inbox already has several, yours might not render, and that’s entirely on Google’s side.

Keep these five conditions in mind before you build your campaign around annotations. They explain most of the “why isn’t it showing” questions you’ll run into.

A word on tracking

Here’s a real limitation to know before you launch: Gmail doesn’t give ESPs a way to track clicks on individual carousel items. Those clicks won’t show up in your campaign’s click metrics.

Two ways to work around it:

• Add UTM parameters to each carousel item's URL and track traffic in your analytics tool.

• Use Batch conversion goals to connect the campaign to business outcomes like conversions and revenue, rather than clicks alone.

Worth the setup

Email annotations won’t fit every campaign. But for a mass promotional send with a strong visual, a clear discount, or a product line worth showing off, they turn a line in the inbox into a small storefront. Get your brand allowlisted early, and you’ll have one more way to make your promotions impossible to scroll past.

Want the full technical detail? Check out Google's own documentation on the Promotions tab.