UpdateProxyAddresses.ps1

$Stopwatch = [system.diagnostics.stopwatch]::startNew()

# When set to $true, then no actions will be taken, only tested
# When set to $false, script will perform actions
$WhatIfPreference = $true
If($WhatIfPreference -eq $true) {
	$host.ui.RawUI.ForegroundColor = "Green"
	Write-Host "--- Script is in testing mode, no actions will be taken ---" -ForegroundColor Blue
}
Else {
	$host.ui.RawUI.ForegroundColor = "Yellow"
	Write-Host "!!! Script is in production mode, actions will be taken !!!" -ForegroundColor Blue
	$confirmation = Read-Host -Prompt "To have the script proceed, please enter YES"
	If($confirmation -ne "YES") { Write-Host "Confirmation was incorrect, exiting..."; $host.ui.RawUI.ForegroundColor = "White"; Exit }
}

# Write to log and console output
Function WriteLog {
	Param (
		[string]$LogString,
		[string]$logName
	)
		
	$LogFile = ".\$logName.log"
	$Timestamp = (Get-Date).toString("yyyy/MM/dd HH:mm:ss")
	$LogMessage = "$Timestamp - $LogString"
	If($WhatIfPreference -eq $true) {
		Add-Content $LogFile -value ("--TEST-- " + $LogMessage) -WhatIf:$false
	}
	Else {
		Add-Content $LogFile -value ("--PROD-- " + $LogMessage)
		Write-Host $LogMessage
	}
}

# Update an ADUser object with a proxy address, either primary or not
Function updateProxyAddress {
	
	Param (
		[Microsoft.ActiveDirectory.Management.ADUser]$user,
		[string]$addressToAdd
	)
	
	# Check if the address has already been added
	$alreadyAdded = 0
	ForEach($userAddress in $user.proxyAddresses) {
		If($addressToAdd -eq $userAddress) {
			$alreadyAdded = 1
			WriteLog ($user.samAccountName + " already has a proxy address of: " + $addressToAdd) $tenantName
			break
		}
	}
	# If the address hasn't been added, do so
	If($alreadyadded -eq 0) {
		Set-ADUser -Identity $user.samAccountName -add @{proxyAddresses=($addressToAdd)}
		WriteLog ($user.samAccountName + " now has a proxy address of: " + $addressToAdd) $tenantName
	}
}

$tenantNames = Import-Csv -Path ".\Tenants.csv"

ForEach($tenantName in $tenantNames.tenant) {

	$Users = Import-Csv -Path ".\$tenantName.csv"
	$upnSuffixes = Get-ADForest | Select UPNSuffixes -ExpandProperty UPNSuffixes
	ForEach ($User in $Users) {
		
		$UPN = ($User."User principal name")
		$username = $UPN.split("@")[0]
		$upnSuffix = $UPN.split("@")[1]
		$syncGroup = "Azure AD Sync"
		
		# Get the user from Active Directory if it exists, move on if it doesn't
		$ADUser = Try { 
				Get-ADUser -Identity $username -Properties proxyAddresses, mail
			} 
			Catch {
				WriteLog ("The username '$username' does not exist in Active Directory... continuing.") $tenantName
				Continue
			}
		
		# Update the UPN if needed
		If($ADUser.UserPrincipalName -ne $UPN) {
			Set-ADUser -Identity $username -UserPrincipalName $UPN
			WriteLog ($username + " now has UPN of: " + $UPN) $tenantName
		}
		
		# Update AD account with proxy addresses
		$proxyAddressesToUpdate = ($User."Proxy addresses").split("+")
		ForEach($proxyAddress in $proxyAddressesToUpdate) {
			If($proxyAddress -like "*onmicrosoft.com*") {
				# skip the addresses with onmicrosoft.com
				Continue
			}
			Else {
				If($proxyAddress -like "SMTP:*") {
					$emailToUpdate = $proxyAddress.Substring($proxyAddress.IndexOf(":")+1)
					If($ADUser.mail -eq $emailToUpdate) {
						WriteLog ($username + " already has a mail attribute of: " + $emailToUpdate) $tenantName
					}
					Else {
						Set-ADUser -Identity $username -EmailAddress $emailToUpdate
						WriteLog ($username + " now has a mail attribute of: " + $emailToUpdate) $tenantName
					}
				}
				updateProxyAddress $ADUser $proxyAddress
			}
		}
		
		# Add user to the sync group
		$members = Get-ADGroupMember -Identity $syncGroup
		If($members -contains $username) {
			WriteLog ($username + " is already a member of the " + $syncGroup + " group") $tenantName
		}
		Else {
			Add-ADGroupMember -Identity $syncGroup -Members $username
			WriteLog ($username + " has been added as a member to the " + $syncGroup + " group") $tenantName
		}
	}
}

$host.ui.RawUI.ForegroundColor = "White"

$Stopwatch.Stop()
Write-Host ("Script ran for " + $Stopwatch.Elapsed.TotalSeconds)