Microsoft is expanding its office AI Copilot with a new feature: from now on, it lists all file attachments that a user has sent or received via email. Anyone looking for an invoice, a quote, or a contract from an older email gets a ready-made overview instead of a tedious inbox search. A paid Copilot license for the Microsoft 365 account is required.
Copilot now automatically searches emails for attachments
Until now, employees had to think for themselves about which email contained a file and manually search the inbox. Copilot now takes over this search on command: a simple question like “Show me all attachments from Ms. Krüger from the last four weeks” delivers a ready-made list with file name, sender, and date. A click opens the file directly, without having to search for the original message.
An example from office life: an accounts clerk remembers that a supplier sent an invoice by email three weeks ago but does not know the exact subject or date. Instead of sifting through the inbox with various search terms, she asks Copilot for all attachments from this sender during the relevant period and gets the invoice directly for selection.
Microsoft calls the feature in its own release notes for Microsoft 365 Copilot “List email attachments” and states it has rolled out worldwide since July 29, 2026. Copilot in Outlook has long been able to revise email drafts directly; the new attachment list adds a search across messages already sent and received.
The attachment list saves time, especially when searching for invoices
Anyone who handles emails with documents daily knows the problem: an important file is buried somewhere in the inbox, but the subject line is long forgotten. This is exactly where the new feature helps, since it does not search the text of the emails but specifically the attached files. That is especially useful for recurring tasks such as filing invoices, delivery notes, contracts, or quotes, which would otherwise have to be tracked down one by one.
According to Microsoft, a search that used to take several minutes and multiple attempts now takes just seconds. The list also shows who sent a file and when, so attachments can be found even when only the sender’s name or a rough time frame is known. For teams that communicate a lot by email with customers or suppliers, this can noticeably shorten daily filing and search work.
A paid Copilot license is required on top of the office subscription
The new attachment list is not available to everyone who uses Microsoft 365. It belongs to the paid add-on license Microsoft 365 Copilot, which costs roughly 18 to 26 euros per user per month depending on the plan and must be booked on top of an existing business or enterprise subscription, as a price comparison for Germany shows. The free Copilot Chat version, which many companies already have included in their subscription, does not read real mailbox data according to Microsoft’s own explanation of the Copilot variants and therefore does not offer the attachment search. The feature is available on the web as well as in the Windows, Mac, iOS, and Android apps – including in Germany and the EU.
Here is how to use the feature in practice:
- Open Copilot Chat, for example in Outlook, in the browser, or in the Windows app.
- Ask a question about attachments, for instance by sender or time period.
- Go through the resulting list of file name, sender, and date.
- Open or download the desired file directly from the list.
What matters now is how reliably Copilot performs once a mailbox has grown over years and holds thousands of attachments – early user reports on that are still missing. It also remains open whether Microsoft will eventually bring the feature to the free Copilot Chat version or keep it reserved for the paid add-on permanently. Anyone using the attachment search should still stay cautious: company and customer data remain stored on Microsoft’s servers, so the usual internal rules for handling confidential attachments continue to apply unchanged.
