I'm testing EV for a new SIP trunk. Inbound calls work great, but outbound do not.

When looking at a trace in Snooper I see this:
From: "Test User"<sip:test.user@domain.com>;tag=49353b50be;epid=2584a7025e

As I understand it I should see the actual phone number in E.164 format after sip:

It appears I'm missing some rules, probably under Trunk Configuration\ Calling number translation rules? Could someone point me in the right direction.

You should see the E.164, and translation rules likely aren't the issue.  Are you watching S4 on the mediation server role?  That's what you should be looking at in the logger to assess.  If you're watching SIPStack elsewhere, you may be watching the wrong side of the call before the mediation server transcodes it and sends it on.

Likely it is sending E.164, but there's something the Telco doesn't quite like about what you're sending.  You should be able to see a SIP error returned back that will help you troubleshoot.

Anthony thank you for your reply.

I was tracing on the client, but did a trace on the mediation server now. It's similar, but I do see E.164 in parts of the trace, most of it is still From: "Test User"<sip:test.user@domain.com>;

The error received is SIP/2.0 604 Does not exist anywhere.

The full ms-diagnostics-public: 10604;reason="Gateway responded with 604 Does Not Exist Anywhere";component="MediationServer";SipResponse="604";SipResponseText="Does not exist anywhere"

I'd gladly share the entire trace (only 52KB) privately if you're willing and if it would help at all.