List Mailboxes with Custom Quotas and Export to CSV
get-mailbox -resultsize unlimited | where-object { $_.UseDatabaseQuotaDefaults -eq $false } | select-object DisplayName,Database,UseDatabaseQuotaDefaults,ProhibitSendReceiveQuota | export-csv '.\user-quotas.csv'
Find Recipients that Use a Particular Email Domain
get-recipient -resultsize unlimited | where { $_.EmailAddresses -like "*@domain.com" }
Find Out Which Mailboxes Have a Forwarder Configured
Get-Mailbox -resultsize unlimited | Where {$_.ForwardingAddress -ne $null} | FL Name, ForwardingAddress, DeliverToMailboxAndForward
List the Users with Archive Mailboxes
Get-Mailbox -resultsize unlimited | where {$_.ArchiveDatabase -ne $null} | ft name, database, archivedatabase, archivename, archivequota, archivewarningquota, retentionpolicy -Auto
List All Mailboxes in a Database
Get-Mailbox -Database <DatabaseName>
List All Archive Mailboxes in a Database
Get-Mailbox -Database <DatabaseName> -archive
List All Arbitration Mailboxes in a Database
Get-Mailbox -Database <DatabaseName> -Arbitration