This article covers
Can emojis be used in the email subject lines?
Emojis are not supported in Chargebee emails. Ensure you don’t include emojis in your emails and if you are using the Grammarly plugin you have to temporarily disable the app while publishing the email notification.
You may experience an error in your app when you have Grammarly enabled or add an emoji as follows,
The value ? is invalid
The value ? is invalid
To avoid this, disable Grammarly plugin temporarily and publish the notification.