I just enabled HTTP Strict Transport Security (HSTS) (https://tools.ietf.org/html/draft-hodges-strict-transport-sec) markers on a bunch of web servers that offer HTTPS.
on 12/16/2010 – Made popular on 12/16/2010
The IETF appears to have had a draft to specify a null mx record whereby a domain would not handle mail and mail delivery systems would fail and return a undeliverable system immediately by directing a domain's only MX record to '.' (c/f http://tools.ietf.org/html/draft-delany-nullmx-00)
Is this draft specification followed by most mail servers out there and worth setting up?