I was trying to mark an email as "Important" in Gmail and accidentally archived it.
Now I cannot locate it, since there is no "archive" label anywhere.
How do I get it back?
Click on All Mail on the left. When you see the message, open it, and choose the Move to Inbox option to "un-archive" it.
Alternatively, you can use the search feature to locate the message (the search box should be towards the top of the Gmail page).
For more details visit Gmail Help.
If you want to search for more than one archived email, entering the following into the search bar will list all your previously archived emails:
has:nouserlabels -in:Sent -in:Chat -in:Draft -in:Inbox
Just search for
An archived email is just an email with the inbox label removed. Search for it, or open a label that it should be in, then click on move to inbox.
In addition to the other answers that show how to find your answer again, you can always get it back immediately after archiving it by clicking "Undo" in the message that appears just after the action:
I have used this "undo" feature many times. Also works for deleted messages.
Archiving an email is just a solution to hide so many emails from Inbox. You can anytime view these emails on label "All Mails" shown on left panel on gmail.
If you can remember who is the sender or his mail id or part of his name, try to search with this information in the search box on the top of the page.