A client of ours has a primary email address of company.net. Mail flow is fine and working as expected. However, there is an engineering dept in the company that has a Linux-based mail server and they want to allow it to send email to the Exchange 2010 infrastructure. The subdomain is eng.company.net
They tried sending out an email and it got bounced back, claiming that the sender was not recognized. What do I need to do with DNS to make this work?
The original message was received at Wed, 12 Oct 2011 22:33:07 -0400 from localhost [127.0.0.1]
----- Transcript of session follows ----- ... while talking to mail.stelect.softserv.com.cn.:
<<< 450 4.1.8 <email@example.com>: Sender address rejected: Domain not found <firstname.lastname@example.org>... Deferred: 450 4.1.8 <email@example.com>: Sender address rejected: Domain not found <<< 554 5.5.1 Error: no valid recipients
Warning: message still undelivered after 4 hours Will keep trying until message is 5 days old