Undeliverable to my other domain emails not on Office365 for business RRS feed

  • Question

  • Most of the personnel are on Office365 ProPlus with their emails coming from our webhoster (they use Rackspace). I want to leave Rackspace (call that domain1) and deploy to Office 365 for business. I am doing a test on O365 for Business.  My new exchange email is set up on another domain (call that domain2) that we own.  I can receive emails from everyone in and out of domain1 but I can't send them to anyone in domain1. (anything outside like gmail is no problem)  I receive and undeliverable message saying that the recipient was not found.

    My thought is that O365 for business thinks that the users on domain 1 (those on Office365 ProPlus and Rackspace) have their emails on O365 for business but they don't and thus "JaneDoe wasn't found at

    Can anyone help please?!

    Tuesday, October 27, 2015 7:20 PM