Common SPF errors include:
SPF none: The domain name does not resolve or have an SPF record
SPF neutral: The domain does not definitively state that the sending IP address is authorized
SPF hard fail: The client is not permitted to send mail from the domain
SPF soft fail: The client is probably not allowed to send mail but is in transition
SPF temperror: There is a temporary error retrieving records, such as a DNS timeout
SPF permerror: There is a permanent error due to an incorrectly formatted SPF record