Limiting The Attachment Window Size in Thunderbird

[for Mozilla Thunderbird users]
Ever get an email message in Thunderbird, with so many files attached, the attachment pane takes over the message viewing area? In Mozilla Thunderbird, you can set a limit to the height of the attachments pane.

Open a text editor, such as Notepad, and paste this text:
#attachmentList {max-height: 4em !important;}

Save the file as userChrome.css (not userChrome.css.txt), and put it the \chrome\ folder of your Thunderbird profile folder.

However, there is one caveat. If you do receive a message with so many attachments, that the height limit is exceeded, there will not be a scrollbar for you to browse through the rest. You can use the menu File–>Attachments to see the full list.

UPDATE: Try the script in comment #1 first.