thunderbird 3 very very big inbox size for imap account

[Gianluca Cecchi]

On Mon, 14 Dec 2009 17:02:08 +0100 Luc MAIGNAN wrote:
> Hi,
> by default, even in an imap account, TB3 downloads messages to allow users to read fastly theirs emails.
> It is a feature you can disable by the options.

Ok, but we are talking of about 1000 X less than 1MB messsages in total.
This gives less than 1Gb of size for plain messages.
Add some overhead....
How do you reach 22 times the plain size????