Viewing the sender reputation statuses

The FortiMail unit tracks SMTP client behavior to limit deliveries of those clients sending excessive spam messages, infected email, or messages to invalid recipients. Should clients continue delivering these types of messages, their connection attempts are temporarily or permanently rejected. Sender reputation is managed by the FortiMail unit and requires no administration.

For more information on enabling sender reputation and configuring the score thresholds, see “Configuring sender reputation options”.

Table 6: Viewing the sender reputation statuses
GUI item	Description
Search (button)	Click to filter the displayed entries. For more information, see “Filtering sender reputation score entries”.
IP	The IP address of the SMTP client.
Score	The SMTP client’s current sender reputation score.
State	Lists the action that the sender reputation feature is currently performing for delivery attempts from the SMTP client. • Score controlled: The action is determined by comparing the current Score value to the thresholds in the session profile.
Last Modified	Lists the time and date the sender reputation score was most recently modified.

Sender reputation is a predominantly automatic antispam feature, requiring little or no maintenance. For each connecting SMTP client (sometimes called a sender), the sender reputation feature records the sender IP address and the number of good email and bad email from the sender.

The sender reputation feature calculates the sender’s current reputation score using the ratio of good email to bad email. and performs an action based on that score.

The FortiMail unit calculates the sender reputation score using statistics up to 12 hours old, with more recent statistics influencing the score more than older statistics. The sender reputation score decreases (improves) as time passes where the sender has not sent spam. The score itself ranges from 0 to 100, with 0 representing a completely acceptable sender, and 100 being a totally unacceptable sender.

To determine which action the FortiMail unit will perform after it calculates the sender reputation score, the FortiMail unit compares the score to three score thresholds which you can configure in the session profile:

1. Throttle client at: For scores less than this threshold, senders are allowed to deliver email without restrictions. For scores greater than this threshold but less than the temporary fail threshold, senders are rate-limited in the number of email messages that they can deliver per hour, expressed as either an absolute number or as a percentage of the number sent during the previous hour. If a sender exceeds the limit and keeps sending email, the FortiMail unit will send temporary failure codes to the sender. See descriptions for Temporary fail in “Configuring sender reputation options”.

2. Temporarily fail: For scores greater than this threshold but less than the reject threshold, the FortiMail unit replies to senders with a temporary failure code, delaying delivery and requiring senders to retry later when their score is reduced.

If the SMTP client does not attempt any email deliveries for more than 12 hours, the SMTP client’s sender reputation entry is deleted, and a subsequent delivery attempt is regarded as a new SMTP client by the sender reputation feature.


	Although sender reputation entries are used for only 12 hours after last delivery attempt, the entry may still appear in list of sender reputation scores.