Migrating Folders to Gmail as Nestedby David WeedmarkUpdated August 23, 2018
Nested folders, where one folder contains another, are a valuable way of organizing email on most email client software, like Microsoft Outlook, Thunderbird or Apple Mail. If you are migrating messages to Google Gmail, you can keep your folders and nested folders intact by using Gmail nested labels. Gmail uses IMAP (Internet Message Access Protocol) to link your Gmail account to your email client software, so that any messages or folders in your Gmail account folder on the client software are stored on the Gmail Web page, organized by labels using the same names.
Creating Nested Labels
Open a new Web browser window and log in to your Gmail account. Click the "Gear" button in the upper-right corner of the page. Select "Gmail Settings."
Click the "Label" tab at the top of the Gmail settings page. Scroll to the bottom of the page and click the "Create New Label" button.
Type a name in the text field and click "Create" to make a new label. Once you have labels added, you can then add a nested label beneath it. Click the "Nest Label Under" check box and then select the label you want it nested under. Click "Create."
Look for you new labels in the left menu of the Gmail page. Click the "Arrow" on the left of each label to display nested labels under it.
Enable IMAP in your Gmail account by clicking the "Gear" button on the upper-right corner of the Web page. Select "Gmail Settings," then click "Forwarding and POP/IMAP." Select "Enable IMAP."
Launch your email client program, such as Microsoft Outlook or Thunderbird. Select the "Add Account" option, usually located in the Account Settings. Enter your Name, Gmail email account address and password. If the client asks for an account type, select "IMAP."
Wait for your email client to download your Gmail. How long this takes will depend on your Internet connection and the number of messages you have in Gmail.
Expand the new "Gmail" folder in your email client. All of your labels and nested labels are displayed as folders and nested folders in your Gmail account folder.
Drag any emails you want to migrate to Gmail into a nested folder under your Gmail account folder. These will be displayed on your Gmail web page in the corresponding label.
Copy any folders into your Gmail account folder in your email client. These messages will appear on your Gmail web page under a new label with the same name.
Migrating multiple emails to Gmail may take several hours or a couple of days, depending on how many emails you migrate. It may be a good idea to start the migration before going to bed, then look for them on your Gmail Web page the next morning.
You will not be able to delete nested folders under Gmail in your client software until you also delete the labels on your Gmail Web page.