Not receive imessage without wifi or data.
I tested three iPhones, myself, my husband's, and my daughter's. The iPhone models are iPhone 11 (ios 16.5), iPhone 8, iPhone 6 (ios 12.5.7).
- If we all have iMessage turned on, and we all have wifi/data, there is no problem.
- If one person turns of wifi and data, this person can send SMS text message to other people. However, this person (the one without wifi or data) cannot receive other people's imessage before connecting to wifi or data. Note that even if the recipient does not have wifi or data plan, our message is automatically sent as "iMessage" if we have wifi or data plan. This behavior suggests that iPhone does not have the capability of receiving "iMessage" as "SMS text" if they don't have wifi or data.
- On the other hand, texting with people using android phones is very smooth. So we will need to rely on android phone if we lose wifi or used up data plan, which is not convenient.
I think this could be an internal bug with iPhone system - people can send "imessage" as "SMS text" if there is no wifi or data, meaning that people can receive messages sent as "SMS text", but they cannot receive "imessage" as "SMS text" if there is no wifi or data. I searched the forum, and found that people have reported this issue since 2013, but still not fixed.
This issue is not limited to iPhone models or ios version - we have a range of iPhone models and ios versions, and they all have the same issue.
Suggestion: Enable receiving "iMessage" as "SMS text" if there is no wifi or data plan.