We are sending your messages through our service to the recipient’s network instantly. However, you have to note that every carrier has own list of rules in order to seek and filter out spam messages. These rules are especially strict in some geographical regions due to the high volume of spam.
Carriers can flag your messages as spam just after several similar sent messages or if similar messages were sent to the same recipient during the short period of time.
Depending on internal rules, carrier can change your sender ID or remove completely flagged messages from delivery.