while cheking in Queue Viewerthis kind of message showing reciver is not able to recieving mails from my exchange" 451 4.4.0 primary target IP address responded with " 421 4.2.1 unable to connect . " Attempted Failover to alternate host, but that did not succeed. Either there are no alternate hosts, or delivery failed to all alternate hosts. suggest me some solution for above error.thxDinku

what is the version of the exchange are you using. Is this Exchange 2003 or 2007?Any smart host on the SMTP or the send connector? Try to take off (just for testing) the smart host entry and see if that works.Raj

2007 Exchange