PhilElliott

DNS Seems ok and the destination IP's resolve fine, ISP is looking into it now see where that go's.

Hi Just need some expert opinion is with an odd exchange 2010 issue. We are having trouble with e-mailing certain schools in the local authority, The e-mails just sit in the queue with 451 4.4.0 Primary target IP address responded with: "421 4.2.1 Unable to connect" and exchange reports the smtp port on the other schools server did not respond, The local authority says its a problem at our end, yet we have no issue with the majority of other schools in the area. bit lost on this one Cheers Phil