MAIL ADDRESS GENERATION POLICY WITH DUPLICATE CHECKING

Currently, there is no policy in Active Roles to enforce uniqueness, as such.

However, some attributes do have uniqueness enforced by Active Directory, notably the samAccountName.

If you create a policy so that the User's email address includes the User's samAccountName attribute, then this will essentially ensure that it is unique.

You're going to have to implement this with a script policy that you fire using an OnPreCreate Handler.

Something like this:

Function OnPreCreate ($Request)
{

# <implement some code to acquire stored credentials for Exchange> and assign to "$UserCredential">

# Load Exchange cmdlets

$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri http://<FQDN of Exchange server>/PowerShell/ -Authentication Kerberos -Credential $UserCredential
Import-PSSession $Session

# Implement whatever formula you like for your e-mail address
# Sample below first.last@domain.com

$ProposedEmail = $Request.get("firstname") + "." + $Request.get("sn") + "@domain.com"

$GoodEmail = $False

While ($GoodEmail -eq $false)
{
# See if our proposed address is in use anywhere in Exchange
$EmailCheck = Get-Recipient $ProposedEmailAddress

If ($EmailCheck -eq $null)
{
# If we get nothing back from the Get-Recipient, set our good flag and ignore the
# the rest of the code in the loop
$GoodEmail = $true
continue
}

# Calculate the numeric suffix

$NumericSuffix += 1

$NumericSuffixString = $NumericSuffix.tostring()

# Rebuild the email address with the suffix

$ProposedEmail = $Request.get("firstname") + "." + $Request.get("sn") + $NumericSuffixString + "@domain.com"


} # End of While loop

# Add the new email into the create transaction (i.e. ActiveRoles Request object)
$Request.Put("targetaddress",$ProposedEmail)

# Kill the PoSh Session with Exchange

Get-PSSession | Remove-PSSession

} # End of Handler