Earlier quoted context omitted.
Sending unsolicited automated emails, even for good, may be considered rude as well.
Really? Do people seriously have this notion? Yes, sending actual spam is rude. But an unsolicited automated email can easily be deleted, especially if it's one time. I would never associate "rude" with that, maybe "annoying" at worst.
Also for ref: http://dontevenreply.com/view.php?post=99