For some time, an email signature like
Please consider the environment before printing this email. Join the campaign at http://thinkBeforePrinting.org
was not uncommon, sites even providing guidance and further information. I, personally, always hated stuff like that, only surpassed by legal cruft seen in emails governed by law jerks, some of them definitely funny.
Clearly, the printing emails instead of reading them online has an expiry date as people read their mails on smart devices, even executives. But, the time is ripe for a new disclaimer, this time not only affecting the mail itself but mostly it’s attachment:
Please consider the privacy before sharing this email and it's attachments with your seemingly free document sharing system of choice. Remain self-determined, respect the privacy of your co-workers and join the campaign at https://sdeem.org
No, that domain doesn’t exist. If it would exist, you would be able to read about the ever increasing amount of information what get’s shared with us, our increasing inability to cope with that bulk load of data and the almost-crime you commit when trying to remain in digital anonymity.