I have 2 exchange 2010 servers in different sites in one domain, connected with isa 2006 vpn. Also i have 2 2003 exchange servers in this sites, but all mailboxes were moved out of them. Now i've got a situation:
1) server 1 can send and get mail from internet
2) server2 can send mail, bat can not get it from exchange server1
3) all mail for server2 stuck in queue on server1 with error: 451 4.4.0 primary target ip address responded with 421 4.4.1 Connection timed out. Attempted failover to alternate host, but that did not succeed. Either there are no alternate hosts, or delivery failed to all alternate hosts.
next hop domain: site2
delivery type: SMTP Relay to Remote Active Directory Site
ps I tried to connect by telnet frov server1 to server2, an it was ok