We wanted an overview of which domains our users were using in a certain country (Netherlands in this case). So, a simple Powershell snippet that counts all unique domains it encounters in the ProxyAddresses field of all users under a certain OU.

Note that if you have set contacts / forwarders, some domains that appear may not actually be accepted domains in your exchange organization.

#Author: Jos Lieben (OGD)
#Date: 13-06-2016
#Script help: www.liebensraum.nl
#Purpose: retrieve all unique domains in use under a specific OU and count them
#Requirements:
#active directory PS module
########

ipmo activedirectory

$users = get-aduser -Filter * -Properties * -SearchBase "OU=Netherlands,OU=Countries,DC=lieben,DC=nu" -SearchScope SubTree

$domains = @{}
foreach($user in $users){

$emails = $user.ProxyAddresses
foreach($email in $emails){
$domain = $email.Split("@")[1]
if($domain){
$domains[$domain] += 1
}
}

}

Write-Output $domains

A demonstration of one way to get shared mailbox permissions exported to a CSV file. We needed both users, groups and users in groups (so, a recursive search). Only Shared mailboxes had to be included, we could identity these by a simple rule:

the first portion of the primary email address does not contain a dot

See line 126 and 127 for this rule if you need a different method.

Edit: make sure you replace CED\ with your own domain! Sorry bout that…

This export excludes Deny permissions and looks for users in groups up to 2 levels deep. Credits to Piotrek for his Get-ADNestedGroupMember function.

Script source: Continue reading Exporting shared mailbox permissions to a CSV →

If, for some reason, you want to see which domains in your exchange organisation are not being used (not registered in the ProxyAddresses fields of your users), use below snippet in the Exchange Powershell Module.

Note: this does NOT (yet) check for domains used in Public Folders or Mail Contacts.

$mailboxes = get-mailbox -Resultsize Unlimited
$groups = get-distributiongroup -Resultsize Unlimited
$domains = Get-AcceptedDomain
$output = @()

foreach ($domain in $domains){

 $obj = New-Object PSObject
 $obj | Add-Member NoteProperty domainName($domain.DomainName)
 $obj | Add-Member NoteProperty domainType($domain.DomainType)
 $res = $mailboxes | where-object {$_.EmailAddresses -Match $domain.DomainName}
 if(-not $res){
 $res = $groups | where-object {$_.EmailAddresses -Match $domain.DomainName}
 }
 if($res){
 $obj | Add-Member NoteProperty inUse("YES")
 }else{
 $obj | Add-Member NoteProperty inUse("NO")
 }
 $output += $obj
}

Write-Output $output