How is it supposed to look?

I'll give you another picture. The first one is from Thunderbird and the second one is from Gmail. The top line of the picture says: Newsletter with the latest news. Problems reading it? See it in the browser. /hans peter

View (Alt-V) - Message Body As - Original HTML

Thanks Christ1, I suspected it could be a setting issue but did not find it. It was also a new phenomenon. Could something have happened in connection with an update? That it has been changed to Plain text? / hans peter

It's most likely something you changed inadvertently.