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No mention was made of the concept again until a first attempt at an SPF-like specification was published in 2002 on the IETF "namedroppers" mailing list by Dana Valerie Lank (née Green), who was unaware of the 2000 mention of the idea.
The very next day, Paul Vixie posted his own SPF-like specification on the same list.
MDaemon supports Sender Policy Framework (SPF) to help verify sending servers and protect against spoofing and phishing, which are two common types of email forgery in which the sender of the message attempts to make the message appear to be coming from someone else. SPF is a means whereby domains can also publish sender records to identify those locations authorized to send messages.
By performing an SPF lookup on incoming messages, MDaemon can attempt to determine whether or not the sending server is permitted to deliver mail for the purported sending domain, and consequently determine whether or not the sender When this option is enabled, MDaemon will perform a DNS query for SPF record data on each incoming message's purported sender, to ensure that the sending server is permitted to send messages on its behalf.
The host MDaemon will verify is taken from the By default authenticated connections are exempt from SPF queries.