Sender Policy Framework
The "Why" tool should explain why a message was rejected. If you used it only as a test tool, you have to consider this perspective, so if it says: This mail should have been accepted. What should now me? What it's telling you is that from the SPF record's point of view, it successfully authorized the IP address.
So just wait a moment and then try again to to send a message. The message should have arrived within this time.