When i send SMS, the recipient receives the message but I get a 'failed to send' notification. Just changed provider

Hey there Juliefw,

That is a strange issue to occur, especially since you already checked with that contact and they mentioned receiving your text message. We'd like to help by learning more about what's happening, along with ruling out some possible causes:

1. If this started to occur immediately after changing providers, have you reached out to your provider to make sure everything is good from their end, along with everything set up correctly with your account?
2. Does this only occur with one specific contact, and is iOS 16.4.1(a) the exact version showing under Settings > General > About?
3. Sometimes unexpected behavior can be resolved with a restart: Restart your iPhone

Cheers!