= Colored Quote Bars =
It has long annoyed me that Thunderbird sometimes treats the '>' characters in excerpts from diffs as reply markers and draws a blue line instead of the actual characters from the E-mail.

{{{
#!html
<img src="/share/flow-bars.png" id="emailFlowImg" style="float: right" />
}}}

I finally found some talk about how to disable that feature [http://forums.mozillazine.org/viewtopic.php?t=86514 here].

Put this in ''~/.thunderbird/*.default/chrome/userContent.css'':
{{{
  blockquote[type=cite] {
    padding-bottom: 0 ! important;
    padding-top: 0 ! important;
    padding-left: 0 ! important;
    border-left: none ! important;
    border-right: none ! important;
  }
}}}

Set the following options:
{{{
  user_pref("mail.quoted_graphical", false);
  user_pref("mailnews.display.disable_format_flowed_support", true);
}}}

And the bars go away.  Along the way, I noticed that if ''format=flow'' is included in the ''Content-Type'' header, Thunderbird does the right thing.  So, the source of these E-mails is partly to blame, but I am happy that there is something I can do about it for now.