Determine which users have logged into Outlook Web App (OWA)

Discovering which users have logged into Outlook Web App (OWA) compared to those who haven’t is a bit of a challenge in Exchange Online and Exchange Server 2013/2016. One method is to make use of the fact that prior to first login, a user won’t have selected their language. Using this piece of knowledge allows us to perform a (somewhat rudimentary) evaluation of which users probably have logged into OWA.

Connect to Exchange PowerShell and run the following:

Get-Mailbox -ResultSize:unlimited | Get-MailboxRegionalConfiguration

Easy! This will show you each mailbox and by evaluating the “Language” value for each, you can determine if a user’s logged into OWA or not. Let’s make it even easier:

The really easy way

# Show me all the mailboxes that have probably not logged into OWA
Get-Mailbox -ResultSize:unlimited | Get-MailboxRegionalConfiguration | Where-Object {$null -eq $_.Language} 
# Tell me how many people have logged into OWA versus those who haven't (Those with a language will have a value, blanks have not logged in)
Get-Mailbox -ResultSize:unlimited | Get-MailboxRegionalConfiguration | Group-Object Language

Cmdlets used in this post

Written on July 12, 2016