qmail - tcpserver variables defined by libSPF

tcpserver Global Vars:
SPF_ACTION | Type of action to take based on SPF result
SPF_TARPIT | Enable/Disable tarpitting
SPF_TARPIT_TIME | How long to tarpit for
SPF_EXPLAIN_STATE | Enable/Disable 'SPF Explanations'
SPF_EXPLANATION | Define the Explanation to message provide
SPF_TRUSTED_STATE | Enable/Disable 'Trusted Forwarder' mode
SPF_TRUSTED_FORWARDER | Define the Trusted Forwarder SPF Query to execute
SPF_GUESS_STATE | Enable/Disable 'Best Guess' mode
SPF_BEST_GUESS | Define the Best Guess SPF Query to execute
SPF_HEADER_STATE | Enable/Disable 'Received-SPF:' header tagging
SPF_DEBUG_STATE | Enable/Disable libSPF debug logging (/var/log/spf.log)
By setting these in your environment with appropriate values you can nicely alter the behaviour of libSPF for an individual person or groups of people on your network. A great example is by placing SPF_ACTION inside of tcp.smtp and setting it to a 0 for 127.0.0.1.
127.:allow,RELAYCLIENT="",RBLSMTPD="",SPF_ACTION="0"
This way 127.0.0.1 never has SPF checks performed on them. I'm sure you get the idea.