How do I ensure G Suite folders containing more than 1000 messages will be migrated?

IMAP access for desktop clients such as Thunderbird or Outlook Express

You can either enable or disable POP and IMAP for your users via the simple process below. POP access is automatically enabled for your users.However, note that this action will apply to all users in your domain. If IMAP is disabled, users can no longer access their POP/IMAP settings in the Gmail interface, nor will they be able to access their mail via POP/IMAP (such as through Google Desktop), even if previously enabled.

1. Sign in to the Google Admin console.
2. From the dashboard, go to Apps > G Suite > Gmail > Advanced settings.
3. In the Organizations section, select the organizational unit for which you want to configure settings.
4. Under POP and IMAP Access, select or clear the checkbox for Disable POP and IMAP access for all users in the domain.

It may take 15-30 minutes for IMAP and POP changes to take effect. As long as the box is cleared, users can configure POP and IMAP access for a host of clients.

Removing folder size limits on IMAP folders

G Suite has a setting that can limit the number of messages in an IMAP folder. If this is configured, this will restrict MigrationWiz so that it can only retrieve and migrate that number of messages from each folder.

Follow these steps to see if this has been set by a user, and how to change it so that there is no limit set:

1. Log in to the account.
2. Click on the gear icon in the upper right-hand side of the window, and choose Settings.
3. Click on the Forwarding and POP/IMAP tab.
4. Under the IMAP Access heading, look for Folder Size Limits.
5. Ensure that Do not limit the number of messages in an IMAP folder (default) is selected.

 Note: To further clarify the implications of this setting: If the limit has been set (e.g., to 1,000 as per the default suggestion), then if folders contain more than 1000 items, they will be truncated at 1000 items. This means that MigrationWiz will only be able to migrate 1000 emails from each folder.

Showing All Mail label and other labels in Gmail:

1. Sign into your Gmail account.
2. Click on the gear icon at the top right of the Gmail window.
3. Click on Settings.
4. Go to the Labels tab.
5. Checkmark Show in IMAP for All Mail, and for any other label you want to include in an IMAP client, or migrate.