For OTP and transactional messages, use your own private transactional SenderID. It's whitelisted like a bank, so it reaches every Kuwait number, even Blacklist/DND ones.
Why the public promotional SenderID is bad for OTP:
How to whitelist (upgrade promotional to transactional):
See also: SenderID types and Blacklist/DND.
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+ What is a Blacklist/DND number, and how do I fix it?