Archiving Mail (this text is from the Gmail help page)
Archiving lets you tidy up your inbox by moving messages out of your inbox while retaining other labels you may have added, so you don't have to delete anything. It's like moving something into a filing cabinet for safekeeping, rather than putting it in the trash can. Any message you've archived can be found by clicking on "All Mail" on the left side of your Gmail page. You can also find a message you've archived by clicking on any other labels you've applied to it, or by searching for it.
Note: When someone responds to a message you've archived, the conversation containing that message will reappear in your inbox.
To archive messages:
- In your inbox, select the message by checking the box next to the sender's name.
- Click the Archive button in the toolbar above your message list.
- If you have a message open, you can also archive it by clicking the Archive button above the message.
To move an archived message back to your inbox, follow these steps:
- Click All Mail. (If you don't see All Mail along the left side of your Gmail page, click the More drop-down menu at the bottom of your labels list.)
- Check the box next to the sender's name.
- Click the Move to Inbox button.
If you'd like an option to automatically archive messages after you've sent replies:
- Click the gear icon and choose Settings.
- Locate the Send and Archive setting and choose the option you prefer.
- Click Save Changes at the bottom of the page.
Once you enable the setting, you'll see a new button at the bottom of the page when you reply to messages. When you're done writing, click Send & Archive to send the reply and archive the previous message in one step, or click Send to send your reply but leave the original message in your inbox.