You can have it delete the message after the forward. Only thing is once you do this, then you will lose the original message with the CID info. You can have it delete from the second mailbox going back to the first. I would recommend the second mailbox being one that isn't tied to another extension as then the vm for that extension don't get forwarded if not needed. As for the original mailbox do not delete message after forwarding. Once the mailbox alert call is answered, that will stop the chain. We use this at our office. Just remember that the system will try 3 times from a mailbox to deliver the message in that 15 minute span. So if you need it done sooner than that. Then set your forwarding timer to 10 or even 5 minutes.