I’ve been using Sinch's SMS API for a high-volume marketing campaign, but I’m encountering significant delivery delays when sending bulk messages. The delays are affecting the campaign’s effectiveness, as time-sensitive messages aren’t reaching custo...
When I send SMS via API to one number it delivers fine. When same code do it for another number it is not delivered. Saying the "337 - Invalid optional parameter"Both numbers are "verified" so they should be able to receive SMS from SinchCode that I ...
I've been trying to get started with the SMS API. The create batch request works but I don't receive any message to my (verified) phone number. In the message search table I can see that the message was rejected by sinch, but I don't know why. Here a...