Scenario: You want to use Get-ADUser to find all Exchange mailboxes in your environment.
Scriptlet: Running the following will provide you with the detail:
#First, lets store some results into $1 for every mailbox
$1 = Get-ADUser -filter {HomeMDB -ne ‘$null’} -Properties MailNickName, HomeMDB, DisplayName| Select MailNickName, HomeMDB, DisplayName
#Now its time to play with your data
#Grab a count of mailboxes Excluding the HealthMailboxes
($1 | Where MailNickName -notlike “HealthMailbox*”).Count
#Grab a count of mailboxes per DB Excluding the HealthMailboxes
$1 | Where MailNickName -notlike “Healthmailbox*” | Group HomeMDB | Sort Name
#Filter mailboxes on a specific database
$1 | Where HomeMDB -like “CN=DB01*”