My Outlook search cannot find the email I know exists

I start the morning with Outlook open because that is still where most of my work begins. I know there is an email from yesterday with the detail I need before a meeting, so I type the sender's name and a phrase from the message into search.

Nothing useful comes back. I try All Mailboxes, Current Folder, a date filter, and the sender's address. I know the message exists because I saw it on my phone, but desktop Outlook behaves as if it was never sent.

I eventually find the email by scrolling through a folder and checking a thread manually. That solves the immediate problem, but it costs the focused half hour I was meant to use preparing the update.

Later, I need another old message with an attachment. Now I do not trust search, so I start second-guessing every folder, archive, deleted item, and device. The small win is that I find what I need eventually. The cost is that Outlook has stopped feeling like a reliable memory for my work.

What I want is simple: a search routine I can trust. I need to know which search scope, filters, folders, sync settings, and fallback checks to use before I waste another morning proving an email exists.