I have been having a lot of problems since yesterday evening around 8PM in Orlando, FL on my 64 6s+ trying to send and receive iMessages. I keep getting "Failed to send" errors, even though the other person said they did in fact receive them as iMessages. It also attempts to send every message as a text, but then when I go to my computer, all of the messages my iPhone identified as sent via text, actually sent via iMessage in reality. I have soft reset and toggled iMessages on and off numerous times. I am about to do a clean restore. Anyone else experiencing problems?
Probably system issues, which can be checked via the link below. Even if everything shows green, it's probably not anything to do suddenly with your particular iphone. I would call apple. https://www.apple.com/support/systemstatus/