Warning: group or other writeable:

[John]

I am seeing the above message associated with the following files -
/usr/lib/postfix/./sbin/lmtp
/usr/lib/postfix/./libpostfix-tls.so.1
/usr/lib/postfix/./libpostfix-util.so.1
/usr/lib/postfix/./libpostfix-dns.so.1
/usr/lib/postfix/./libpostfix-master.so.1
/usr/lib/postfix/./libpostfix-global.so.1
/usr/lib/postfix/sbin/./lmtp

My problem is that I cannot find these files - where should I look and 
why are they group/other writeable?

John A