Hi,
I asked on the Office 365 forums and they sent me here, so I'll just paste my original question below.
We're using Office 365 and want to send e-mail via our own e-mail client on behalf of a connected account.
That means my.account@contoso.onmicrosoft.com has his private e-mail account my.account@t-online.de connected and can send e-mail on behalf of this account when connected via Exchange connection (Outlook) to his onmicrosoft.com account.
As stated in the original thread (http://community.office365.com/en-us/forums/158/t/211058.aspx) this is not possible using SMTP (not allowed to send as this sender) but could be possible using mapi.
Original question:
"Our Outlook client is able to to send on behalf of the connected account using an Exchange connection.
Therefore it should be possible to use any mapi client to achieve this, right?
Is there a document that explains how Exchange handles this protocol wise?"
Thanks in advance.