Open Gmail
In the search bar, type the sender, subject, or keyword from the archived email
Click the search result to open the archived email
Click the Move to inbox button at the top
Or select the email and choose Move to inbox from the menu
To find archived mail faster, open All Mail from the left sidebar
Select the archived email
Click Move to inbox
On mobile, open the Gmail app
Use Search or open All Mail
Open the archived email
Tap the three-dot menu
Tap Move to inbox