Hi,

To cut a long story short due to a company takeover, all our internal users are getting new email accounts setup by the parent company, however they are keeping their original AD credentials. The new emails are not "Internal" email address as they are hosted on our parent companies Office 365 tennant in a seperate domain. They are all soon going to be using this new email address as their default Send As address so all tickets raised will be from the new address. I am currently trying to get SDP to email external contacts (which everyone will be classed as one soon) but i just get a pop up saying "sending notification failed" anyone able to help?