Privacy leak: email open event

[gsurrel]

Checklist

• I have used the search function to see if someone else has already submitted the same bug report.
• I will describe the problem with as much detail as possible.

App

K-9 Mail

App version

17.0

Where did you get the app from?

F-Droid

Android version

9

Device model

Galaxy S8

Steps to reproduce

1. Go to https://www.EmailPrivacyTester.com/ and put an email address you can access to
2. Open the link in the received email to open the dashboard, and click the button to send the test email
3. On K9 Mail, open the 2nd email

Expected behavior

No requests proving that I opened the email should have escaped the device.

Actual behavior

Check the dashboard: the "CSS background-image" tracker has been activated

Logs

No response

[gsurrel]

Hummm, I just retried twice and got different results. Maybe another agent triggered something in parallel. Can I let you check whether it effectively applies and close accordingly?