How does sender id framework work

These SPF records identify authorized outgoing e-mail servers. If the IP addresses match, the e-mail message is authenticated and delivered to the receiver. If the IP addresses do not match, the e-mail message fails authentication and is not delivered.

Neutral Published Sender ID data is explicitly inconclusive. Softfail This value indicates a weaker type of failure. PermError There is an unrecoverable error, such as an error in the record format. Resent-Sender 2. Resent-From 3. Sender 4. The Sender ID filter determines the actual e-mail domain by locating the first definition of the following RFC message headers in this order: 1.

A sender or user sends an e-mail message from an e-mail client or Web interface. The recipient's inbound e-mail server receives the e-mail message. The receiving MTA determines whether the outbound e-mail server's IP address matches the IP addresses that are authorized to send e-mail for the domain.

Based on the SPF record syntax, the pass or fail verdict, the reputation data, and the content filtering score, the receiving MTA delivers the e-mail message to the inbox, a junk or bulk folder, or a quarantine folder. For more information about how the Sender ID status is displayed in messages, see Antispam stamps. Stamp status : The Sender ID agent stamps the Sender ID status in the metadata of the message, and allows the delivery of the message to continue.

This is the default option. Because the source server assumes the message was sent, it doesn't try to resend the message in the same session. For more information about how to configure the action to take for spoofed mail and unreachable DNS servers, see Sender ID procedures. The more organizations that configure SPF records for their domains, the more effectively Sender ID is able to identify spoofed messages.

To support the Sender ID infrastructure, you need to create SPF records for the domains that your organization sends messages from. These can be deleted, bounced back to the sender, sent to a spam trap, or quarantined.

The sender ID system can be configured in the way that best suits the needs of the users. Some users want to know what kinds of email are being flagged, while others may want people attempting to spoof them to know that the emails are not getting through. The disadvantage to sender ID is that if records are outdated or erroneous, as can happen, email may be trapped in the system when it is actually legitimate.

It can take up to 48 hours for changes of information to propagate across the DNS system.