If your IMAP mailbox is full or starting to approach the disk space capacity you may need to archive messages by copying them to an offline location on your computer. This will allow you to free up space in your mailbox without permanently deleting your messages.
This guide will explain how to create a local folder within Mac Mail and archive messages from your IMAP mailbox to local storage on your Mac.
Creating an archive mailbox
If you don’t already have a archive mailbox for archiving mail you can create one by following these steps:
- Got to the Mailbox menu.
- Select New Mailbox.
- Make sure the Location for the new mailbox is set to On My Mac and enter a Name for the mailbox.
- Select OK to create the mailbox. You should now see this has been added to the mailbox list in Mac Mail under the heading On My Mac.
Move mail to the archive mailbox
To archive messages from your IMAP mailbox you simply need to drag/drop the message from the IMAP folders to the location folder added in Mac Mail.
You can move messages individually or in bulk. If you’re copying messages in bulk try to limit copy operations to a few hundred emails at a time to avoid any risk of the copy operation timing out mid-transfer.