Last night I wrote up a long email on an IMAP Gmail account in TB, but my network was down while writing it and TB couldn't save to drafts while composing. It popped up a dialog informing of me of this, giving me only two options - Retry or Cancel. I chose Retry a few times with no luck, then figured I would go back to finishing my email and would try again when done. However, I couldn't continue typing the email with the dialog box up, so hit Cancel to get rid of it. But this closed my entire compose window and I lost 30m of work typing it up. Not saved to drafts or anything else. I know TB can't save an IMAP email to the remote drafts folder if there's no network connectivity, but for the love of god please don't create a situation where the only options are to leave the Retry/Cancel dialog box open and blocking the compose window, or hitting cancel and losing your entire message. Maybe a "Try again later" option that unblocks the compose window without closing it, or something. I love Firefox and Thunderbird and everything you guys do for the web, but this issue has got me walking on eggshells with TB now.