I have the outbound calls working via HTTP, and have some logic to determine if the correct response code was entered. However, when I poll the status of the call, it says “Call Succeeded” regardless of whether the right code was entered or not.
I have in my script an exit with different expressions, but […]

According to callwithus.com SIP configuration:
SIP server (or proxy, or domain) sip.callwithus.com
SIP proxy (or “Outbound Proxy”) leave blank
STUN server stun.callwithus.com
Username (or User ID) username
Password password
Auth name (or Auth ID) username
Display Name (used for callerId information when you place a call) Your name
Register (or Send registration request) Yes
Silence suppression (or Voice Activity Detection) On
Use DNS SRV Yes […]

Tried many different settings in SIP, but just cannot connect. No problems whatsovever using X-Lite.
Here are the settings I use in X-Lite, please tell me what I should enter in the voicent fields.
USER DETAILS
Display Name: {my name}
User Name: 2210000
Password: {my password}
Authorisation User Name: 2210000
Domain: lon-pbx-5.gradwell.net
DOMAIN PROXY
Register with domain and recieve incoming calls (ticked)
Send Outbound via: […]