After you migrate from Exchange 2000 Server or Exchange 2003 Server to Exchange Server 2007, some 3rd party applications or mail servers may fail to send to, or relay mail through your Exchange Server 2007. These 3rd party applications or mail servers include sender alias or recipient alias in MAIL FROM: or RCPT TO: command without full email domain name appended.
These messages are rejected by Exchange Server 2007 with “501 5.1.7 Invalid Address” response. However, the same 3rd party applications or mail servers still work with your previous versions of Exchange Server, like Exchange 2000 or 2003.
This problem occurs because by default the receive connector in Exchange Server 2007 does not have its default domain value set. This is unlike the behavior in Exchange 2000 or 2003 where it automatically appended the default domain to values that are submitted to MAIL FROM: or RCPT TO: in the message envelope by a sending server if no domain name is provided.
In Exchange Server 2007, the default domain value on the receive connector is not set by default. If no domain name is specified in the MAIL FROM: or RCPT TO: commands, Exchange Server 2007 rejects the message with “501 5.1.7 Invalid Address” response.
To resolve this problem, perform the following steps to set the default domain value on the receive connector from Exchange Management Shell:
1. Click Start, click All Programs, click Microsoft Exchange Server 2007 and click Exchange Management Shell.
2. Run the following cmdlet to view the current setting of the default domain value on your receive connector:
Get-ReceiveConnector -identity <YourReceiveConnectorName> |fl
In the output, notice that the value of DefaultDomain is blank by default.
3. Run the following cmdlet to set the default domain value:
Set-ReceiveConnector -identity “<YourReceiveConnectorName>” -DefaultDomain “<YourSMTPDomainName>”
For example, Set-ReceiveConnector -identity “Default EX2007MAIL” -DefaultDomain “contoso.com”
4. Run Get-ReceiveConnector -identity <YourReceiveConnectorName> |fl cmdlet again and verify that the DefaultDomain has been set in the output.