I am currently using vendors to deliver Ringless voice messages to Cell phones and Landlines (digital mailboxes).
I am looking to develop our own solution. It has to be able to drop voice messages directly into the mailbox without the phone ringing. This is critical. Some services ring the number twice and "trick" the system into going into the voicemail. This causes the phone to ring periodically which makes it non compliant. I need a solution that will recognize as many cell phone carriers as possible and as many digital landlines as possible. Success rate of messages has to be high. If you are interested in this project, please let me know. Thank you!