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Add outbound MX record SPF

Solution: Add a TXT record for your domain
@ v=spf1 mx ip4:mail.host.com ~all

Issue: Somehow external mailservers need to validate the server it received mail from is legitimate.  This apparently is not always an issue, but I figured I would set this up correctly, regardless.

In the past we would simply add an MX record with the highest priority (even if the server was simply an outbound server).  This really is not a great approach.  The SPF (TXT) record of type MX is the right way to accomplish this.


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