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Outgoing IP address & NLB

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Outgoing IP address & NLB - 23.May2008 6:51:10 AM

admintola

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Joined: 14.Apr.2008
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The outgoing IP address for email in an ISA protected network is the first IP on the external NIC. If this does not match the MX record for the domain some companies reject that email as a means of fighting SPAM eg AOL and Comcast.
What does one do to get around this issue when you want to implement NLB on ISA servers since the the servers will have different first IP addresses?
Will ISA default to using the first Virtual IP as the sending IP address?

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RE: Outgoing IP address & NLB - 23.May2008 6:59:45 AM

admintola

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Joined: 14.Apr.2008
Status: offline

Found the answer.

If you are running ISA Server Enterprise Edition and you have enabled Network Load Balancing (NLB) integration, you should create an MX record for each array member using the dedicated IP address for each array member instead of the virtual IP address of the NLB cluster. If you use the virtual IP address as the MX record, you can receive e-mail messages. However, e-mail messages sent to a server that performs a reverse DNS lookup on your domain will be rejected. For more information, see the section, Common E-Mail Validation Checks and Sending Internet E-Mail Messages with ISA Server.

(in reply to admintola)

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