Lync Server 2013 Std & Exchange 2013 CU3 voicemail setup: Attempts to route to servers in an Exchange UM Dialplan failed

We are doing a proof-of-concept for Lync Enterprise Voice in our organization. Everything is on-premises.

Lync 2013 is setup and seems to be working fine. I've got some snom phones (720, 710, 300, 370 and I am able to use them and direct dial other extensions no problem and use them to make calls to Lync users (I haven't tried external dialing yet). I've setup the phones to have 4 digit extensions (e.g. 5243) because we may have less DID's than phones.

My problem is that I can't seem to get voicemail going properly. I can't dial it from the phones, and pressing the voicemail button just gives the error message "Temporarily unavailable: voicemail"

On the Lync 2013 server I see this error message:

I've setup some dial plans and I have followed the directions for setting up UM on Exchange 2013 (create um dial plan & IP gateway, configure umservice & umcallrouter, assign certificates, run ExchUCUtil.ps1) and Lync 2013 (OcsUmUtil.exe)

I think it might have something to do with the dial plan, as that is something I am really weak on understanding.

Here is what I have setup:

Global

#1 normalization rule

Pattern to match:^(\d{4})$

Translation rule: +17803922450;ext=$1

#2 normalization rule

\+?[\s()\-\./]*1?[\s()\-\./]*\(?\s*([2-9]\d\d)\s*\)?[\s()\-\./]*(\d\d\d)[\s()\-\./]*(\d\d\d\d)[\s]*

+1$1$2$3

Under the UM Dial plan > Outlook Voice Access I've setup the following

E.164

+17803922451

Outlook Voice Access Numbers:

+17803922451

Here is what is setup under ocsumutil.exe:

Dial Plan: CAEDM_UM_DIAL_PLAN.network.domain.ca

Name: CAEDM_UM_DIAL_PLAN

SIP Addres: sip:CAEDM_UM_DIAL_PLAN.network.domain.ca.ca @ network.domain.ca

Server or pool: lync2013.network.domain.ca

Use this pilot number from Exchange UM: +17803922451

I think it's gotta be with those numbers, but I really don't know what.

Thanks.