Why is my phone sending symbols in place of my messages?

[iMore Question]

So far, this has only happened to my boyfriend. I have an iPhone 6s on Verizon, he has some android on T-mobile. I send a text and it'll send weird letters like a "D" with a "<" on top oriented upwards and other weird symbols. It happens all the time and it's annoying because he doesn't get but 3-4 words of what I sent. Can someone help?

 

[Trees]

Although an older discussion, the problems in the thread below sound similar to what you're experiencing. It may not hurt to contact Verizon Support to see if they have some recommendations. Others who have experienced the problem with iPhone 6S and are on Verizon may also be able to help. As a point of reference, I have an iPhone 6S+, and have not experienced the problem when sending SMS to Android or Blackberry smartphones.
Sending SMS and receiver is getting ASCII characters instead of text - Windows Central Forums