List users with mismatches msRTCSIP-PrimaryUserAddress and proxyAddresses attributes.

List-MismatchedSIP.ps1

Import-Module ActiveDirectory

$users = Get-ADUser -Server dc01.drewchapin.com -Properties proxyAddresses,msRTCSIP-PrimaryUserAddress
#  -Filter { physicalDeliveryOfficeName -eq "Location Name" }

ForEach( $user in $users )
{
    $sip1 = $user.'msRTCSIP-PrimaryUserAddress'
    $sip2 = $user.proxyAddresses | Where { $_ -like "SIP:*" }

    if( ($sip1 -eq $null -xor $sip2 -eq $null) -or (
    $sip1 -ne $null -and $sip2 -ne $null -and 
    $sip1.Substring(4).toLower() -ne $sip2.Substring(4).toLower()) )
    {
        Write-Host "Name = $user.Name;    msRTCSIP-PrimaryUserAddress = $sip1;    proxyAddresses = $sip2"
    }
}