Hi,
I am using the latest version of egroupware 19.1.20200318 with docker, mysql and nginx as web server.
When opening an email with double click, its opens into a new browser window. In this new window when trying to forward an email as an attachment, by clicking on more and forward as attachment not works.
Nothing is shown in nginx logs and I have check it with my current (upgrade) and a new clean installation.
Regards.