If you have SpamAssassin installed and see “
Can't locate Mail/SPF/Query.pm in @INC...” in your error logs, you need to install Mail::SPF::Query.
SpamAssassin uses SPF to detect header and email-source forgery – very important in determining if e-mail is legitimate or not.
To install Mail::SPF::Query, run these commands as root:
perl -MCPAN -e shell
If you haven’t yet added SPF records to your DNS, you can find out more at the Sender Policy Framework site