P.S. In Thunderbird, select the message
of the person you want to kill file.

Go to "Message", "Create Filter From Message"
and choose "Delete Message" (the default).

P.P.S. Your server, "Eternal-September.ORG"
censors my (HTML) posts.

Please, if you want to converse with me,
sign up with this server:

Usenet.BlueWorldHosting.COM
nntpSwitch.BlueWorldHosting.COM:119

Unlike Pan, Mozilla Thunderbird knows HTML.