Florian Kulzer wrote:
[...] Your problem boils down to the fact that Thunderbird does not provide any convenient commands to make use of that information. When I was getting increasingly annoyed by this myself (with Mozilla Mail), I came across the following Thunderbird extension: http://www.cweiske.de/misc_extensions.htm#mailinglistheader [...]
Even without the extension, responding to the list is easy; it takes me four keystrokes to do so. This is how you Tbird users can do it: Add debian-user@lists.debian.org to your address book, and give it a nickname like "debl" or something. When you reply to a list message, select the e-mail address text and type in "debl"; the nickname will be replaced with the list's address.