I have experimented a bit with this. I run the outbound connections through a flow that has an AVA that can detect and converse with the Assist. The hardest part is getting the AVA to escalate to the agent right after navigating through Assist. As for a full mailbox, it's usually detected by the provided SIT tones and recorded as a voicemail, even though you can't leave one. I would guess the AVA could listen for that and output to the flow that the mailbox was full, so the number could be called again.
For your second, you have two choices. You could use the inbound ANI to search your contact list for the number and then mark it as uncallable. The mechanics of doing that could be a bit daunting. I would suggest a pre-call rule that checks the number being called against interactions from the last XX hours. If you see an inbound call, just mark it as uncallable or skip it.
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Robert Wakefield-Carl
ttec Digital
Sr. Director - Innovation Architects
Robert.WC@ttecdigital.comhttps://www.ttecDigital.comhttps://RobertWC.Blogspot.com------------------------------