Found an issue following an update to perl-DBD-MySQL (4.039-1.fc24 arrived here 2016-11-24) after which amavisd-new was scanning mail as clean and processing as spam.
I'm using SQL lookups and found this affected versions 2.11.0-4 and 2.10.1-7 of amavisd-new on my systems.
Downgrading perl-DBD-MySQL appears to have resolved the problem. HTH A
