Checking Disk Usage by Mailboxes

If you need to check disk usage for a mail account, go to Mail tab and check the Usage gauge for the mail account in question. You can see actual usage for all mail accounts by clicking Refresh Usage Stats. Keep in mind that all mail sent to a mail account whose usage is greater than the mailbox size will be rejected.

Note: Mailbox usage statistics shown under the "Usage" column on the "Email Addresses" tab may differ from that shown in Statistics or collected manually via the CLI commands (for example, the -du utility). Statistics in the "Usage" column reflects only the Maildir++ size, which does not include service files that can be stored in the Maildir folders (for example, dovecot.index.cache).