"550 5.7.1 Unable to relay" displayed on inbound emails after migrating from SBS '03 to SBS '11

We just migrated from SBS 2003 to SBS 2011 using the SBS 2011 migration tool. We are now receiving reports that, after migrating, that some inbound emails are reporting a "550 5.7.1 Unable to relay" error. We are using exchange 2010 on the SBS 2011 server. Any thoughts on how to allow emails to flow inbound properly?
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Maen Abu-TabanjehNetwork Administrator, Network ConsultantCommented:
read this ..


One thing to keep in mind, is you would need 2 IP Address.  This is unless you specify a remote server IP Address on the relay connector.  When the Hub Transport receives a relay attempt from a server, if it notices there is a connector with an explicitly defined ip address instead of, it will use that connector which has the relay enabled negating the need for a second IP Address for relaying.

Make sure you follow all those steps including doing the Add-ADPermission for the connector to allow the anonymous logon group to relay using that connector.

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