Mail Detective tries to determine the geographical origin of email messages in your INBOX via geolocation by parsing the message headers for the sender's IP address. Simply drag the email from your mail program and drop it onto the app’s window - Mail Detective will tell you the country and, if this information is available, the city from which the email was sent.
If your mail program does not support Drag and Drop of messages, you can also copy the email headers and paste it into the app.
Please note that Mail Detective will need internet access to work. If the message is older than 24 hours, the city of origin may be outdated and no longer be correct. In the cases where the sender has used a generic email provider, such as iCloud or Gmail, Mail Detective may not always be able to trace the email back to the sender. In those cases, the location of the webmail service will be displayed.
Mail Detective now supports Dark Mode on macOS Mojave.