How do I find if the mail received was sent from OWA or Microsoft Outlook?

If you look at the email header information the x-mailer header entry will say Microsoft Outlook Web Access whereas if it is sent with Outlook it will say something like Microsoft Office Outlook.

Lee

depends what logging you have enabled on your exchange, each time a owa user logs in it should create an event on the exchange server if that helps?

Hi lsavidge,

From MS Outlook when I right click on any Email I get Options - Message options, Then below I find 'Internet headers:', which is empty for all our domain Emails from Outlook as well as OWA. But anything received out of domain I find details in this 'Internet headers:' box.

So now when you say Email header Information ,X-mail header entry, where can I find this?

In standard Exchange & Outlook setup you do not have X-mailer header.
So as I wrote there's no easy way to know it from message.

if the correct logging is enabled, you'll see six or seven events logged each time an OWA user logs on. You'll typically see event IDs 1170, 1136, 1137, 1007, and 1009, and you might see more than one of each. These events will tell you who logged on and when

Thnaks to all of you