Question: Iphone 5s won't send text messages
I have Iphone 5s with 10.2 iOS, and I'm unable to send messages (texts) to some numbers. iMessages) are working just fine. Reception signal is good, I do not have any blockage of outgoing traffic for my phone number. I can text without problems when using non-iOS phone (Android or some old phone).
It seems that somehow Apple is blocking some phone numbers from my iCloud account. Other people can regularly send messages to these numbers.
There is a "Not delivered" note next to messages with with sign "!".
I've tried to reset the phone, delete conversation and contacts, but no luck.
Apple is still not yet supported officially in my country so I can't ask directly.
iPhone 5s, iOS 10.2