spfquery
Query Sender Policy Framework records to validate e-mail senders.
TLDR
Check if an IP address is allowed to send an e-mail from the specified e-mail address
$ spfquery -ip [8.8.8.8] -sender [sender@example.com]
Turn on debugging output
$ spfquery -ip [8.8.8.8] -sender [sender@example.com] --debug
