What occurs when configuring separate incoming mail policies?

Which type of attack is prevented by configuring file reputation filtering and file analysis features?

A network administrator is modifying an outgoing mail policy to enable domain protection for the organization. A DNS entry is created that has the public key.
Which two headers will be used as matching criteria in the outgoing mail policy? (Choose two.)

When DKIM signing is configured, which DNS record must be updated to load the DKIM public signing key?

When outbreak filters are configured, which two actions are used to protect users from outbreaks?
(Choose two.)