I have a network with two sites, previously both sites accessed Exchange mailboxes in Site1. Site2 was installed with CAS, Hub and Mailbox roles and the intention of moving Site2 users off to the Site2 Exchange. All 3 roles are on a server in Site1.
Everything so far looks fine except the original Site1 cannot deliver mail to mailboxes in Site2 - they sit in the queues instead. The network is fully routed and there's no firewall rules blocking any traffic on the VPN link. The BPA doesn't help much either and the queues just say "421 4.2.1 Unable to connect. Attempted failover to alternate host., but that did not suceed. Either there are no alternate hosts, or delivery failed to all alternate hosts. ". I can telnet into port25 on the Site2 server from site1.
Can anyone please help??