So i have 1 exchange server hosting 2 domains. When external domain emails to both internal domains. Email is received on 1 of the internal domain. All other email seems to come through fine on both domains. After reading up i think it might be something to do reverse DNS lookup.
1. Both Domains are hosted and have mx records pointing to server.
mail.xyz.com ( should i change this mx record to mail.abc.com)
2. Smtp server is using a smart host of the hosting company. Using primary domain abc.com smart host.
Also would like to note that I am fairly new to exchange with multiple domains. I have searched all over google and am bit stumped. Any help is appreciated.