/usr/share/perl5/Mail/Milter/ is in libmail-milter-perl 0.07-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/perl5/Mail/Milter/Chain.pm
/usr/share/perl5/Mail/Milter/ContextWrapper.pm
/usr/share/perl5/Mail/Milter/Module/
/usr/share/perl5/Mail/Milter/Module/AccessDB.pm
/usr/share/perl5/Mail/Milter/Module/ConnectDNSBL.pm
/usr/share/perl5/Mail/Milter/Module/ConnectMatchesHostname.pm
/usr/share/perl5/Mail/Milter/Module/ConnectRegex.pm
/usr/share/perl5/Mail/Milter/Module/HeaderFromMissing.pm
/usr/share/perl5/Mail/Milter/Module/HeaderRegex.pm
/usr/share/perl5/Mail/Milter/Module/HeaderValidateMIME.pm
/usr/share/perl5/Mail/Milter/Module/HeloRawLiteral.pm
/usr/share/perl5/Mail/Milter/Module/HeloRegex.pm
/usr/share/perl5/Mail/Milter/Module/HeloUnqualified.pm
/usr/share/perl5/Mail/Milter/Module/MailBogusNull.pm
/usr/share/perl5/Mail/Milter/Module/MailDomainDNSBL.pm
/usr/share/perl5/Mail/Milter/Module/MailDomainDotMX.pm
/usr/share/perl5/Mail/Milter/Module/SPF.pm
/usr/share/perl5/Mail/Milter/Module/VirusBounceSpew.pm
/usr/share/perl5/Mail/Milter/Object.pm
/usr/share/perl5/Mail/Milter/Wrapper/
/usr/share/perl5/Mail/Milter/Wrapper.pm
/usr/share/perl5/Mail/Milter/Wrapper/DecodeSRS.pm
/usr/share/perl5/Mail/Milter/Wrapper/DeferToRCPT.pm
/usr/share/perl5/Mail/Milter/Wrapper/RejectMsgEditor.pm