The organization that I work for uses outside firms to conduct email-based surveying and research. We're also hit constantly with phishing attempts and have worked to make sure our users understand that official emails will always come from our domain.
A research firm that I have been recently working with sent me the SPF record they maintain for their clients to include in their own SPF records to allow the firm's servers to send emails on behalf of their domains. However, when I checked the SPF record they want me to include I noticed that it has several includes of its own. When I checked those out, I found that one of the includes ends with "?all". I checked to make sure it would neutral-mark every email by sending myself a spoofed email using research firm's domain and an unsecured smtp sever, and it worked.
Obviously I don't want to include "?all" in my SPF record because it would (seemingly) undo any good the record was doing to begin with. It's not hard to check SPF records, and wouldn't take an attacker long to figure out they could send emails as my domain.
Am I being dense here? The vendor with the "?all" in their SPF record is a nationwide leader in providing survey logistics, and is extremely widely used; I can't imagine that I'm the only customer with concerns about this practice. Is using "?all" more common/reasonable than my understanding of it?