A lookup expansion is also available. It takes an email
address as the key and an IP address as the database:
- $lookup (username@domain} spf {ip.ip.ip.ip}}
+ ${lookup {username@domain} spf {ip.ip.ip.ip}}
The lookup will return the same result strings as they can appear in
$spf_result (pass,fail,softfail,neutral,none,err_perm,err_temp).