Essentially the destination IP address can almost be anything. Anything that according to the ASAs routing table is located behind the "outside" interface. Naturally your server should not connect to itself through the firewall and not through the NAT IP address so this should not be used as a destination.
The NAT configuration looks like any basic Static NAT configuration that binds the public NAT IP address to the local IP address.
The question at the moment would be where is the ACL named "VoIP" attached?
Are you trying to allow traffic to this host/server on the DMZ from the external network? If so then you should be allowing the traffic from the external network. In an ACL that is attached to your "outside" interface.
You can check where ACLs have been attached with the command
show run access-group
As I said, if you wanted to allow HTTPS to this host/server from the public/external network then this ACL rule should be using the ACL that is attached on the "outside" interface.
Furthermore, if you wanted to test connectivity TO this server from the public/external network then you could use this "packet-tracer" command
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...