RatSMS offers lightning-fast OTP delivery with guaranteed accuracy and high uptime, perfect for secure logins, transactions, and user verification. Their easy-to-integrate API and SMPP solutions are designed for developers and businesses that need real-time authentication via SMS. With support for DND and non-DND numbers, RatSMS ensures every OTP reaches the right user without delay. ... https://ratsms.com/otp-bulk-sms-chennai