I cannot seem to find a way to force text only or emulate a screen reader. I'll describe the steps and clicks and maybe you can find the path that way.
While I'm reading a message from this group mail list, I click on the "more" menu selection above the message toward the top of the page. My screen displays three vertical dots for that "More" menu selection, but says "More" when I hover the mouse over it.
In the "More" drop down menu list I select "Filter Messages Like these".
That selection displays a pop up window that displays some search criteria. It includes "Has Words Like" with the value already filled in with "list:(<
digitalvoice.googlegroups.com>)".
Click "Create filter" toward the bottom of that window.
The pop up window will change to a list of options that includes "Never send it to spam". Select that option so it is checked.
Click on "Create filter".
The filter should be created now.
David McAnally
WD5M