We are a company that change the name a few years back (lets call it Company2) and we had the email address: "firstname.lastname@company2.no". There were a few guys that didn't want to be a part of our company and stayed with the same company name (lets call it Company1). They had the email address "firstname.lastname@company1.no". We that changed the name still have the alias @company1.no and main email @company2.no Company1.no is in the accepted domain of Company2's exchange server. Now the problem is: When we send emails to someone we know who works at Company1, that person does not get the email, and the sender (ie. me who have firstname.lastname@company2.no) does not recieve an error message from the server that says: we could not deliver the email. Does anyone have any clue what can cause this? I was thinking it might be that we still have @company1.no aliases.

Are these two different Exchange Organizations? Do these accounts have company1 as an alias? You should be able to use message tracking to see if the message was transferred and if you are an admin of the other org, you should be able to track the message as it comes into the other org?

Yes, two diffrent exchange organizations, Company2 have company1 aliases since we went and started our own company, so for to make sure the customers who forget we are a new company we will still get the emails. I can try using message tracking and I will try to update the problem as i get results.

Yes if you're company2 and you're Exchange is still authoratiative for company1 domain than it will never leave your org. What version of Exchange? If 2003 is company1 still in the recipient policy? If 2007/2010 is company1 still in the accepted domains?James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

Yes if you're company2 and you're Exchange is still authoratiative for company1 domain than it will never leave your org. What version of Exchange? If 2003 is company1 still in the recipient policy? If 2007/2010 is company1 still in the accepted domains?James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

Yes if you're company2 and you're Exchange is still authoratiative for company1 domain than it will never leave your org. What version of Exchange? If 2003 is company1 still in the recipient policy? If 2007/2010 is company1 still in the accepted domains? James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com Company1 is still in the accepted domains. Im looking into if our Exchange is till authoratiative for company1

Yes, I think you need remove recipient policy (for compandy1) and accepted domain (company1), or Exchange(in company2) will do local check for emails send to users@company1.no. Thanks, EvanEvan Liu TechNet Community Support

If it is authoritative, they should be getting an NDR for a user that does not exist on the system when a mail is sent. What can be done, though, is set the accepted domain from authoritative to internal relay and create a new send connector that is scoped to that domain name and use smart hosts to send it over to the other Exchange system.