The semi-stable version of Toby was updated again today with incredible advances in attachment support – number of attachments and filenames are now correctly calculated for all standards-compliant messages, HTML version of the message is no longer counted as an attachment, and others. You can now choose to view both the HTML and plain text version of HTML e-mails as well.

Update: Toby is no longer supported. I recommend using RoundCube Webmail instead.