Do you have an idea how I can manipulate the font-size of text represented in classic block.
Background for this question is that I create a post via email using a plugin called postie. THis plugin is using the classic block to present the content of the email.
content within the Classic Block should use the Body font size set in Customizer > Typography > Body.
If thats not the case then you may find that the post from email is being imported with inline styles – which you can see by selecting the Text/HTML view in the Classic block.