I noticed that the summary part in
[details=Summary]This text will be hidden[/details] is rendered as ordinary text in emails with nothing hinting at the hidden details.
This is what it looks online:
And this is what it looks like in the email
I think it would be great to somehow convey to email recipients that what they are seeing is only the summary of a larger chunk of text.
To start with, it would be good if the black triangle that is shown before the summary online would also be included in the email. In addition, it might even be good to add a link after the summary saying “Click here to see details online” which would open the post online with that particular detail segment expanded (if that is possible at all).