I do not have a seperate AD domain. What I did was in System Manager I created a new recipient list for the new email domain such as @123.net . Then created a new storage group and new mailbox store for these mailboxes. I then created an MX record for this new email domain. Now my Exchange server accepts mail for both @abc.com and @123.net email addresses. What I am trying to do now is login in to Outlook with my profile where my mailbox is in the @abc.com mailbox store and open a @123.net mailbox. The thing is I can open the @123.net mailbox no problem (not a permission issue) but as soon as I do I can no longer send mail, this is when I get the "the operation failed" error. I cannot send mail again until I exit Outlook and open it again. I can then send mail, as long as I do not click on the other mailbox. Also, if I leave the other mailbox open, expanded, and I restart Outlook, I get and error stating "Cannot create the e-mail message because a location to send and recieve messages could not be found. To add a location, click the tools menu, click Services, and then click the Delivery tab" but Outlook is set to deliver to my mailbox" when I click New Message.
Any help is greatly appreciated,