I am using Thunderbird E-mail client v. 18.104.22.168
I would like to filter all HTML encoded messages. For this I created a message filter with a customized header
"Content-Type" but that does not work as expected (no messages are filtered).
The filter looks like that:
"Content-Type" "contains" "text/html"
I did not find any related bug or workaround (no add-ons).
Is my filter wrong? Should I try Thunderbird V. 3 beta?