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Reputation and Authentication
What are Reputation and Authentication?
How does my Reputation affect email delivery?
The behavior of mail server IP Addresses, authenticated domains, and URL's are tracked. Consistent bad behavior will lead to mail delivery issues. Consistent good behavior will reduce mail delivery issues.
How does my Authentication affect email delivery?
Facebook requires either SPF records or DKIM signatures to authenticate mail from your domain. Unauthenticated mail may be rejected or delivered at a slower rate than authenticated mail. Recipients may see warnings that the source of the message could not be verified when reading unauthenticated messages. Mail sent to Facebook applications, such a Groups or Photos, are more likely to be refused if they are not authenticated.
Even if you are unable to publish an SPF record with 'Fail' or 'SoftFail' mechanisms, are unable to publish your entire infrastructure with a 'Pass' mechanism, or are unable to implement DKIM signing on your entire outbound mail system, Facebook encourages administrators to configure domain authentication for as much of their system as possible. This will begin establishing a reputation for your domain and minimize the number of delivery issues encountered.