Overview
Gmail annotations allow Growave notifications to display extra promotional information directly in the Promotions tab of Gmail. Depending on the notification type, Gmail may show:
Deal annotation — a discount highlight
Deal card — a discount card inside the email preview.
Product carousel / Single image preview — a single product image or a product image carousel.
You do not need to add any markup to Growave templates — they already contain the required annotation metadata.
Key benefits
More visibility — discounts or product images can appear before the email is opened.
Automatic markup — no setup required from merchants.
Stronger engagement — annotated messages stand out in the Promotions tab.
Annotation types
Gmail supports several structured annotation types. Growave uses the following:
Deal annotation (in the email preview)
Deal annotation is displayed when either of these fields is available and meets Google’s requirements:
discount description (English + supported currency), or
discount code (UPPERCASE + digits)
Gmail may show the description, the code, or both.
Deal card (inside the email)
Deal card appears only if:
a valid discount description is available and meets Google’s requirements.
the discount code is optional — it will be displayed if it also meets Google’s requirements.
Product carousel
A horizontal set of product images (up to 10) that can display products from your notification.
Product carousel requires:
suitable, high-quality images
supported aspect ratios
an allowlisted sender domain (Google requirement)
Single image preview
Displays one featured product image from the email.
Single image preview also requires allowlisting and full image compliance.
Where these formats are available
According to Google’s rollout:
Product carousel and Single image preview are fully launched on the Gmail mobile app and are not fully supported on Desktop.
Deal annotation is fully launched both on Gmail mobile app and on Desktop.
Merchant requirements
Growave handles annotation markup automatically. Merchants only need to ensure that the input data follows Gmail rules.
1. Discount code format
Gmail accepts discount codes that contain only:
UPPERCASE Latin letters (A–Z)
Digits (0–9)
Consider this when adding discount prefixes in Growave reward rules. Avoid lowercase letters, symbols, spaces, and hyphens.
2. Supported language and currencies
For annotated fields, Gmail supports:
English text for descriptions
currency symbols: $, €, £
If unsupported text or currency symbols are used, Gmail may show only the discount code, or hide the annotation completely.
3. Image requirements (carousels and previews)
To be eligible for Product carousel and Single image preview, product images should follow Google’s guidelines. In practice this means:
using aspect ratios like 4:5, 1:1, or 1.91:1
at least 256×256 px
clean, high-quality product photography
minimal or no text on the image
no circular masks, decorative crops, or icon-style images
the same image for all recipients (no per-recipient personalized URLs)
For the most up-to-date and detailed rules, refer to Google’s official Gmail Promotions / Annotations documentation.
4. Allowlisting your domain
Product carousel and Single image preview annotations require that your sender domain is allowlisted by Google. Deal annotation and Deal card do not require allowlisting.
Using a custom sender domain
If you've set up a custom email domain to send Growave notifications, contact Google at [email protected] and include:
your sending domain(s)
all subdomains used for sending emails
landing page URLs (for example, your homepage)
Google usually reviews such requests within several business days.
Using Growave’s default sender
If you use Growave’s default sender address ([email protected]), no action is required on your side.
When annotations appear
Annotations may appear when:
the message is classified into Gmail Promotions
Gmail determines that all requirements are met (content, images, domain, etc.)
the email is part of a larger send batch (Google’s logic favors messages sent to 100+ recipients)
Gmail chooses to display the annotation based on engagement and inbox conditions
Google does not guarantee annotation display for every message or every recipient.
Supported Growave notifications
Below are all Growave notifications that include annotation metadata.
Rewards notifications
Annotation display depends on the reward type you selected when setting up your reward rules. Supported types:
Amount discount
Percentage discount
Free shipping
These notifications support Deal annotation and Deal card:
Notification | Deal annotation | Deal card |
Reward Redeemed | ✅ | ✅ |
Reward Expiration – Warning | ✅ | ✅ |
Reward Expiration – Last chance | ✅ | ✅ |
Celebrate Birthday | ✅ | ✅ |
Friend Received Referral | ✅ | ✅ |
Referral Completed | ✅ | ✅ |
Tier Unlocked | ✅ | ✅ |
Wishlist notifications
Notification | Product carousel | Deal annotation |
Saved Wishlist Notification 1, 2, 3 | ✅ | ✅ (only if a discount code is added to the email template) |
Wishlist Items On Sale | ✅ | ❌ |
Wishlist Items Back in Stock | ✅ | ❌ |
⚠️ Important
Wishlist notifications are typically unique per customer, not bulk campaigns.
Because Gmail tends to show annotations for larger send volumes:
product carousels in Wishlist emails may rarely appear
deal annotations in Saved Wishlist emails may also be suppressed
However, Growave always includes valid annotation metadata, so Gmail can display these elements whenever all conditions are met.
If you have any questions or need assistance, feel free to contact us at [email protected] or via the chat in the bottom-right corner of your Growave admin panel. We're here to help! 🤗