I am looking at enabling the MailTips in Exchange 2010 but was curious to know whether they will show in the Outlook 2007 client? I am specifically interested in the "The following recipient is outside the organization" message being displayed!
Looks like I have found my answer:
Q: What clients does MailTips support? A: Though the screenshots posted above are from Outlook Web App (known as Outlook Web Access in previous versions), MailTips are also a feature of Outlook 2010. Legacy Outlook/OWA versions are not supported.