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(1) (Stateful Packet Firewall) See stateful inspection.

(2) (Sender Policy Framework) An e-mail authentication system that verifies that the message came from an authorized mail server. SPF is designed to detect messages from spammers and phishers who falsify the sender's IP address in the e-mail header. SPF is an extension to the SMTP mail protocol.

SPF Records
The DNS system identifies the IP address of a receiving mail server with a line of text in the DNS database known as an MX record. DNS also supports a "reverse MX" record, which identifies the sending mail server and is used by SPF. When an e-mail message is received, the mail server checks the SPF record in the DNS to see if it matches the actual IP address of the message. If it does, the e-mail is considered valid. For more information, visit www.spf.pobox.com.

SPF Classic and PRA
There are two approaches to checking e-mail messages via SPF. SPF Classic systems check only the envelope header, while Microsoft's Purported Responsible Address (PRA) method looks at the headers within the message. See Sender ID, Joe Job, spam, phishing, throwaway domain and SMTP.
References in periodicals archive ?
The brand utilizes advanced technologies that provide skin with multiple benefits, including free radical defense and advanced protection against UV-induced damage without the need for higher concentrations of potentially-irritating sunscreen ingredients found in products with high SPF.
Dermatologists suggest applying 1-2 ounce of sunscreen with at least an SPF of 15, 20 minutes before going outdoors to help the skin absorb it well, and reapplying every two hours.
In fact, out of the five mineral sunscreens tested, only two met their SPF claims.
Exuviance Sheer Daily Protector SPF 50 is non-comedogenic, non-acnegenic, non-irritating, non-sensitizing, paraben free, fragrance free and oil free and can be used post-peel.
Water-resistant color cosmetics infused with SPF and soothing antioxidants are also on trend.
The Bayer Applicator Fundamentals Program combined with the Center for the Polyurethane Industries (CPI) SPF Chemical Health and Safety Online Training program provides a best practices guide to safe spray polyurethane foam products and uses.
The Sun Screen Gel SPF 15 is made with Aloe Vera, Watermelon and Cucumber extracts, while the Sun Block Cream SPF 25 is enriched with Jojoba Oil and Wheat Germ Oil.
Fending off the rays is Vichy's Capital Soleil range with Fresh Cream for all skin types and Micro- Fluid Mat for combination and oily skins with SPF 50+ for pounds 13.
SPF is a favorable material that is often utilized for MDF panel production in Quebec, Canada.
Try the Sheer Tint SPF 15 (pounds 26) to even out skin tone or choose a moisturiser specially created for your skin,be it dry,oil or combination.
Start the day by mixing a little bit of Origins Sunny Disposition Liquid Bronzer or Revlon Skinlight Face Illuminator Lotion with your favorite SPF 15 face formula.
UCLA dermatologists rave about Coppertone's Shade and Clinique's Cityblock, both of which have an SPF of 45.