Recovering important email from junk folder in Apple Mail

Received an important email into Junk folder from Docusign.

Dragged it to the Inbox and it disappeared.

Searched all folders for sender "Docusign" and searched every email from today's date- no dice.

How do I recover?

Would rebuild help?

Running Apple mail with iCloud account.

Sonoma 14.2.1

[Re-Titled by Moderator]

Original Title: Junk Mail Disappears