Text messages don't work when my phone is offline.

I read your post twice to try to understand it, and here’s what I think you said.

If an Apple product user sends you a message that would be treated as an iMessage while your Wi-Fi and cellular data are not working, you would like to receive the message as an SMS message. Further, you expect this behavior because you have set Settings > Messages > Send as SMS to “on”.

The key is the setting you turned on is “Send as SMS”. It has nothing to do with how messages are received. You are observing normal behavior.

The sender can force the message to go as SMS by sending as an email. For example, if your cellular carrier were AT&T and your telephone number were (987) 654-3210, I could send an email to 9876543210@txt.att.net and you would receive it as an SMS text message.

Additionally, you are never “forced to use iMessage” for outgoing messages. Remember the sender, not the recipient, controls the protocol.

SMS uses the cellular voice channel, it doesn’t use data, so you don’t need a data connection for pure text (no pictures). iMessage uses data, either cellular or Wi-Fi, so you need one or the other to receive iMessages.

MMS (picture messages to/from non-iPhones) requires cellular data; it cannot use Wi-Fi.

Protobazz wrote:

In practice, this means I miss an extraordinary amount of texts from other iPhone users.

Correct me if I’m wrong, but I believe this is incorrect.

You don’t miss any texts. Some texts are delayed.

OK, so yes, it sounds like the immediacy issue can be solved by either a bigger data plan or more frequent access to Wi-Fi.

This just happened to me now !! What happened any update ? I don’t know what to do ! My phone wont receive or send messages unless I’m on WiFi