To find out where emails really come from or why they took longer, it is often helpful to take a closer look at the email header (i. e. the "meta data", not the content).
You can then see which route the email took, where it was perhaps only forwarded with a delay, and much more.
To be able to analyze the data more precisely (or to forward it to the ZID in case of questions), it is recommended to copy it into a text editor.
Examples of how to get to the email header:
In an open message, you have two options:
Here you can find info about it.
The result will look like this:
In the message, click on the top right
→ Show message details