DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=facebookmail.com;
The selector is named as s-1024-2011-q2. Well, I can understand 1024 bits is used and the key has been in service since Q2 of 2011. Facebook has not changed the key pair for over three years. It is a bad and unacceptable security practice !