Failed outgoing messages can show a red Not Delivered warning, spin forever, or do nothing when you tap send. If regular SMS, MMS, or photos are affected, look beyond iMessage and check cellular, carrier, storage, and Messages settings.
These steps apply to iPhones running recent iOS versions when sending SMS, MMS, RCS where supported, or iMessage.
Does This Affect You?
Use this if messages fail for more than one conversation, especially regular texts and photo messages. The cause is usually connection, carrier configuration, or a stuck Messages app.
Check Connection and Airplane Mode
- Open Control Center and make sure Airplane Mode is off.
- Check signal bars or 5G/LTE status. Move near a window or outside if signal is weak.
- Open Settings > Cellular and make sure Cellular Data is on.
- Scroll in Cellular settings and confirm Messages is allowed to use data if app-level toggles appear.
- Try sending to another contact. If only one conversation fails, start a fresh thread with that person.
Update Carrier Settings and MMS Options
- Connect to Wi-Fi or working cellular data.
- Open Settings > General > About.
- If a carrier settings update appears, tap Update.
- Open Settings > Messages.
- Turn on MMS Messaging for picture messages.
- Turn on Group Messaging if group texts are failing.
- Restart after a SIM or carrier change so new settings fully apply.
Free Space and Restart Messages
- Open Settings > General > iPhone Storage.
- Free space if the iPhone has less than about 1 GB available.
- Review Messages storage for large old attachments and conversations.
- Force-close Messages from the App Switcher.
- Restart the iPhone and try sending again.
Photos and videos need working storage space to process before sending. A nearly full phone can make attachments fail quietly.
More Message Checks
Try Again from the Warning
Tap the red exclamation mark beside a failed message and choose Try Again. If one contact always fails, the thread or recipient may be the issue.
Check Blocked Contacts
Open Settings > Messages > Blocked Contacts. A blocked number can make communication fail without a helpful explanation.
Focus Does Not Stop Sending
Do Not Disturb and Focus silence notifications. They do not normally block outgoing texts, so sending failures should be diagnosed elsewhere.
Use Low Quality Image Mode
For large photos over weak service, turn on Settings > Messages > Low Quality Image Mode so smaller images are less likely to time out.
Sources
- Apple Support: If you cannot send or receive messages on your iPhone
- Apple Support: Update your carrier settings on iPhone
- Apple Support: Free up storage on your iPhone