triangle with I inside

[AC Question]

Sent text messages , all go through except to one person where I received triangle I inside, What does this mean? thanks

 

[Indoler]

Sent text messages , all go through except to one person where I received triangle I inside, What does this mean? thanks

It means "CAUTION! DANGER".
Probably something wrong with that person's device.

 

[Golfdriver97]

The message probably did not go through to them. Are they using an iPhone?