I stumbled upon the following information in an article at http://www.openspf.org/Implementations
The Mail::SPF::Query Perl module was the very first implementation of SPF and was the de facto reference implementation for quite some time. It roughly conforms to the final SPFv1 specification, however due to its long heritage (reaching back to 2003) there are some deviations. In particular, the library does not support the final processing limits and also supports a number of non-standard features, such as best-guess processing and trusted forwarder accreditation checking. That being said, there are currently two library implementations that are known to fully conform to the final SPFv1 specification (RFC 4408): ... Mail::SPF: An object-oriented Perl module that supersedes the old Mail::SPF::Query module. It supports both SPFv1 (v=spf1) and Sender ID (spf2.0) and is very thoroughly documented. Is there a good reason for the QP sender-permited-from plugin use Mail::SPF::Query rather than Mail::SPF along with using best-guess and trusted forwarder by default, or is it only because nobody has ported it to Mail::SPF? -Jared -- Inbound and outbound email scanned for spam and viruses by the DoubleCheck Email Manager: http://www.doublecheckemail.com/
