Apple has updated its support document to address common issues with iMessages, such as messages showing a “Not Delivered” alert, appearing as SMS or RCS in green bubbles, or being sent from your email address instead of your phone number.
According to MacRumors, these issues often occur when users do not activate their eSIM during the initial setup of a new iPhone running iOS 26. If you opt to activate your eSIM later through the Settings app, iMessage does not automatically activate itself.
To resolve this, after setting up your eSIM in Settings, you must manually activate iMessage by following these steps:
- Open the Settings app and tap Apps.
- Select Messages.
- Toggle iMessage off, then back on.
This guidance mainly applies to users who skip the eSIM setup during the iPhone’s initial configuration. It can also affect those who switch carriers and activate a new eSIM through Settings.
This is the second notable iMessage-related issue reported since the launch of iOS 26. Earlier this month, Apple released another support guide to help users who struggle to activate iMessage with their phone numbers.
