There's no doubt about it.
I find it interesting that most (if not all) of us speakers of English use the expression "no doubt..." about something when we do, in fact, have reasonable doubt!
For example: "No doubt he's coming soon."
If we didn't have any doubt about when he might arrive, we would just say: "He's coming soon."
Oh, English language, how I adore your quirks and inconsistancies.
(๑￫‿ฺ￩๑)