Thunderbird infamously places the local copy of IMAP mails (i.e. Effectively a cache) into Appdata\Roaming. It's the single largest directory I have there. Ever

Thunderbird infamously places the local copy of IMAP mails (i.e. Effectively a cache) into Appdata\Roaming. It's the single largest directory I have there. Everything else is quite reasonable in size.