Why can't I send messages while on wi-fi?

When I upgraded from my IPhone 4S to the IPhone 6 Plus a few months ago, I started to notice that when having cell data turned off while at home and using only my WiFi, that some text messages would not come through until my data was turned on. I may go for several days using only WiFi. I receive text messages during this time, but if I leave home and turn on cell data, I might have several text messages come through from days earlier. These can be messages from a group, texts containing photos, or just text messages. No distinction and it's not always the same person/persons. Most all the text messages originate from other IPhone devices. Doesn't make sense why I can receive text messages while on WiFi (and data turned off) some of the time, and other times cell data must be turned on. Anyone else have this problem and what was the solution?

Accepted answers

Weth

All MMS messages (photo, video, long messages), must go over the cellular data network. While it goes over the cellular network, it does not count against your data allotment.

This must be a recent change as we have seen many questions on this.

You you can use message+ app for messages to go over wifi.

All comments

MiiHere

I know on android if you turn off data and use Wi-Fi you can send and receive SMS message, but you cannot send or receive MMS.

Are you using iMessage?

Weth

All MMS messages (photo, video, long messages), must go over the cellular data network. While it goes over the cellular network, it does not count against your data allotment.

This must be a recent change as we have seen many questions on this.

You you can use message+ app for messages to go over wifi.

Cardinal33

Using the standard messages app on the phone. The random messages that sometimes aren't received can be either short text messages, some with pics, and once a group message. So it's never just one type of text. Appreciate your feedback.

Cardinal33

Weth, could you explain using message+ app for messages to go over wifi?

I now understand about the MMS messages needing data network. But not all my missed texts are in this category.

Weth

The Verizon Message app is here:

Verizon Messages by Verizon Wireless

https://appsto.re/us/K7TcL.i

Also keep in mind any text message with a special character, foreign character, accents, emoticons, emojis, odd punctuation, any group text etc etc will be converted to MMS, so it is just not by size.

I am quite sure this is your problem and any message not going while you have data off is for some reason being converted to MMS