Set-CASMailbox vs Set-Mailbox

Hey Guys

I was reading through some documentation on Set-CASMailbox and Set-Mailbox. One of the things I noticed (And maybe I am high) is that set-casmailbox can be used for setting the EMailAddress and the PrimarySMTPAddres. But of course so can Set-mailbox.

Set-CASMailbox

https://technet.microsoft.com/en-us/library/bb125264(v=exchg.150).aspx

Set-Mailbox

https://technet.microsoft.com/en-us/library/bb123981(v=exchg.150).aspx

The question I have is why? and when would I use Set-CASMAilbox vs Set-Mailbox. To set a users emailaddres or primarysmtpaddress?

Thanks,

Robert

Robert