I'm still having trouble understanding your threat model. If you're talking about somebody who can get Hotmail's cooperation, e.g. cops or sysadmins, there's no way you can prevent them from doing anything they want to your incoming mail. If you're worried about crackers guessing your password, then some web-based email systems automatically mark mail as read, some don't, some let you mark it, some let you remark it as unread. (I haven't ever used hotmail, and my cat stopped using it when the Child Online Protection Act required Hotmail to cancel accounts for anybody under 13 years old who didn't have parental permission, so the interface has probably changed since I last saw it.) Are you worried specifically about Hotmail? You're mentioning using gmail to pre-filter your hotmail messages - gmail's going to have similar potential threats, except that it's probably better managed, and if you're going to send the mail to gmail anyway, why not just read it on gmail? In general, if you've sent unencrypted email to an untrusted system, then you've got no way of knowing that it hasn't been read. At 01:09 PM 4/27/2005, Tyler Durden wrote:
Oh...this post was connected to my previous one.
Sorry...my ideas along these lines are still a little foggy but I'll try to articulate.
Basically, let's assume someone with some resources has cracked your email and wants to monitor what you send and receive. let's also assume they don't want you to know it. Let's assume they also are not particularly thrilled about having hotmail know what they're up to (if needs be they can obtain a warrant, etc..., but this is clearly less than desirable compared to more direct techniques). It seems fairly easy to me to (for instance) create a bot that duplicates all of the email and resends it to your hotmail account so that when you log in everything looks fresh and new. (There are probably easier ways to do this via direct hacks of hotmail).
Is there some way to make it evident that someone has opened your email?
Right now, I can't think of anything you could do aside from suggesting that hotmail (or whoever) offer some kind of encryption service.
BUT, it occurs to me that you might be able to have gmail forward your mail to hotmail via some intermediate application you've set up that takes the timestamp and whatever and creates a hash.