With Exchange 2010 Service Pack 1 it became possible to share your calendar with anyone outside of you organization, depending on the Sharing Policy implemented by your Exchange Administrator. Users can then share their calendar via an obfuscated or an relatively public URL without the need for authentication (and SSL for that matter). For more ...

With an On-Premises Exchange 2010 environment an administrator hands out Send-As permission with the Add-ADPermission cmdlet. But I found out that this doesn’t work in Office 365. In this case a P plan (no Dirsync, Federation or such), you can see the result in the screenshot: Funny thing is that if you try Add-MailboxPermission to add Send-As ...