1 of 1 people found this helpful
Hey there! Welcome to our Support Community!
That's a fantastic question! I looked at my personal account usage and saw an incoming message from "500" too but wasn't able to figure out who the message came from when I went through my inbox. I searched high and low to see if we had any info as a company about this message and wasn't able to locate any. I'm sorry but I don't have an answer for you.
I've seen this before myself. Have you ever matched up the times with messages in your phone to see if the phone's texts shows that the message came from 500 or an actual number? If it does show up as a number on your phone but 500 on your bill, it could be how the bill displays an email that came from that phone number.