graeme_p - 8:00 am on Aug 17, 2013 (gmt 0)
@Samizdata, the point is not that you agree to their TOS - you do not. The point is that you agree to let them process your email in accordance with whatever agreement they have with the recipient.
@BeeDeeDubbleU, and delegating to a subordinate is not very different from buying in email service rather than running your own server. Whoever runs the server can process email addressed to you in ways you have agreed to.
Let me boil this down to a simple question. Do you think Gmail's spam filter is an invasion of privacy? If not, in what way is the processing for ad placement a greater invasion of processing for spam filtering?