Don't try to make me responsible for your lapses of care in your email behaviour.
Go boil your head (of legal affairs)
I do love when e-mail senders (who should, and probably do, know better) attach meaningless boilerplate to their messages:
"This email is personal and confidential. If you are not the intended recipient please immediately delete it and notify the sender by email. The contents should not be copied or disclosed to any other person or used for any purpose without permission from the sender."
- If the sender sends something to the wrong place, that's their responsibility.
- Once I have received and read it, the knowledge cannot be expunged and besides, once it is in my mail it is mine to do with as I see fit. It may go against social convention to expose private communications, but by and large - short of being party to an NDA, which cannot be imposed externally - there is no practical reason not to.
- Whilst I respect it and will take steps to protect your privacy and security, others will not and I have no obligation to. It is your affair, not mine. In truth, if you don't take it seriously, then why the hell should I?
Bottom line: If you are worried about the sensitivity of your mail, then TAKE MORE FUCKING CARE over who you send it to!
