Sender Policy Framework (SPF): Safeguarding postal secrecy

Fake sender details on emails are becoming an ever-increasing problem in the digital space. In particular, the overflowing 'spam' and 'phishing' are making their way with the help of 'forged' addresses. The Sender Policy Framework (SPF) is used to control this avalanche of spam.
For each domain, the administrator stores a list of permitted mail transfer agent (MTA) addresses, i.e. servers that are authorized to send emails for this domain. Only those senders included in this list are then authentic, all other emails end up in nirvana.
SPF is not a foolproof system. It does not intercept all unwanted emails because it only recognizes forged sender addresses, but not the spam content itself. On the other hand, SPF is a procedure that makes abusive use legally actionable, provided the recipient system supports SPF.