The little detour over the wrong track led me to the English term mentioned above, with which I then searched further. I'm still leaving the instructions online, as there may be people with older macOS that they'll still work on.
#Apple outlook read receipt update
Update : I have received feedback from several readers that these terminal commands are no longer effective. Terminal commands for mail reading receipts But I didn't want to take any chances for this post. Therefore, it is possible that an identically named software or a corresponding plug-in for e-mail exists and works well. Especially with a sensitive topic such as e-mails, one should perhaps not dare to experiment without a corresponding necessity. on Google Drive and the like - but that didn't seem very trustworthy to me.
#Apple outlook read receipt manuals
I have "Secrets" here and there with other download sources besides that in some other manuals and forums Mac App Store found - e.g.
In the test, I either had the wrong software or the option no longer exists. Secrets is supposed to unlock a point in the Mac system settings that can be used to activate read receipts in macOS Mail. In my test, the system settings entry didn't even show up. But either this only applies to an old version of the app or to another software with the same name. Allegedly, after installing the Secrets App and restarting the Mac, a menu item should appear in the system settings via which the command Request read receipts to for read receipts for e-mails. But that just seems to me to be a free one 1Password-Alternative to be. One looks for Request macOS Mail read receipt, you have a good chance of coming across guides and recommendations that suggest an app called "Secrets". Why the Secrets Password Manager is nonsense
That would also explain why the cloud service is mandatory at Mailbutler. I assume Mailbutler works with an invisible, embedded graphic in the mail and checks whether it has been called. In contrast to iReceiptMail, the read receipt with Mailbutler works without a notification box that the recipient has to click off. But you can still see the ticks that Mailbutler fades in for every mail and shows whether it has been sent, received and read. Sorry for the pixelation, but it has to be for personal data.