Blocking read receipts

Question

Level 1

8 points

Blocking read receipts

A company with which I am in dispute has stated that I opened an e-mail at x time in May 2013. I opened the e-mail either in iCloud or in Mac mail. I use no other e-mail system. The matter that I opened the e-mail was never in dispute. The invasion of privacy that they know what I am doing on my computer troubles me much more.

Initially I believed that this was a question of a read receipt, but in an old post to which I responded

Csound1 has stated categorically

"Apple Mail does not respond to read and / or delivery receipt requests."

and when asked "Then how can the company know when i opened the message?" he replied,

"Ask them, they did not get a receipt from Mail but there are plenty of other resources available to an IT dept, especially at the behest of the legal dept."

Would anyone know what these "other resources" are and, more importantly how one can protect oneself from the them ?

MacBook Pro, Mac OS X (10.7.5)

Posted on Aug 19, 2014 3:05 AM

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Answer 1

barangus

Level 1

10 points

Sep 12, 2014 1:24 PM in response to kip7

An embedded hyperlink to an image will leave a http GET log trace on the server the image came from. That's how newsletter services like ConstantContact et al can track and report to their customers a message-open rate for a mailing campaign. It might be a 1 pixel by 1 pixel gif that has included in the file name a code associated with just that one message.

They can't prove that you opened it only that someone with access to your mail did.

You can sometimes choose to not load images on message open in some services and apps.

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Answer 2

kostby

Level 4

2,964 points

Sep 14, 2014 9:03 PM in response to kip7

Little Snitch from Objective Development allows you to monitor and control much of the network traffic handled by your Mac and your Mac Mail account.

http://www.obdev.at/products/littlesnitch/index.html

You can define temporary and permanent rules to automatically permit or deny these 'hidden' messages once, until the computer is restarted, or permanently, including those sent to and from your Apple Mail account. Understand that denying some or all of the links contained in an email message may prevent some or all of the message content from loading successfully.

As an example, here's one of several Little Snitch notices (with a request to approve or deny the connection) generated using Apple Mail when I opened a retailer's (benign) incoming email attempting to notify the email marketing service that the message was opened.

In my experience with Little Snitch 3.3.4, you WILL NOT EVER receive Little Snitch warning messages about pixel monitors and similar tracking methods contained in email, when that email opened using the provider's own homepage message viewer in your Safari or Firefox browser, although there ARE many links that must be approved in order to successfully connect to such a third-party email provider (Hotmail/Outlook/Live, Yahoo mail or Gmail are the ones I've used.) Those monitor messages are apparently hidden and happen 'behind the scenes' in the browser email interface without your ability to limit or control them.

I've been using Little Snitch for several years, but I do not claim to be an expert, so I cannot affirm that it is true in every case, and also because I have marked hundreds of recurring connection rules "approved" over the years.

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