We have installed and configured Exchange 2013 in our environment (3 CAS Servers and 3 Mailbox Servers) and all is working well so far.
However 2 CAS Servers are in our main site and 1 CAS Server is in a DR site.
We have NLB set up for these 3 CAS servers (IP 192.168.1.1), for our inbound mail (Which goes via a third party), there are 2 routes set up on the third party to send email internally (1 via the main site and 1 for the DR site) but both set up to go to the NLB address internally.
Often we get incomplete packets in the firewall logs as there are 2 rules set up to forward to the same IP internally but from 2 external sources if that makes sense.
3rd Party >>>>>>>>>> CAS01 or CAS02
Do you know if there is a better way of setting this up so email can come in via either route but not show up as incomplete?