Hi, we are in a migration process from a Kerio system to Exchange 2013.
Everything is working fine, except that we have been experiencing this error on the logs and the Exchange 2013 users are getting returned emails.
The remote server is 10.10.10.85
Remote Server at 10.10.10.85 (10.10.10.85) returned '400 4.4.7 Message delayed'
19/12/13 7:21:57 p. m. - Remote Server at 10.10.10.85 (10.10.10.85) returned '451 4.4.0 Primary target IP address responded with: "421 4.4.5 Too many messages from this host last hour." Attempted failover to alternate host, but that did not succeed.
Either there are no alternate hosts, or delivery failed to all alternate hosts. The last endpoint attempted was 10.10.10.85:25'
My question is, is Exchange rejecting the messages or is the other system telling Exchange to slow things a bit?
