Email Message when send Configuration – Question

Hello there, i hope you are fine 🙂
I was sending my configuration several times via E-Mail just for testing purpose.

Then i thought about the E-Mail Message Body, i can actually add a Image there, but after i click on save, it shows a broken icon, like no image is available. When the E-Mail is send, then you will see this //// instead of the image. https://ibb.co/qgSQTJT

My question: Is this a bug or you simply can not add images in the E-Mail? All my plugins that send E-Mails, when i put there a image, it will be added and send normal. I am not sure, maybe your template dont allow to add images or its a bug. It would be nice to add my logo there or a simple design or what ever, you know what i mean?

I would be happy if you can check it by your side. Thank you 🙂