Is Your Mailbox Full? Duplicate Emails May Be the Reason

Your mailbox is full. But why? You delete large attachments, empty the Trash, and remove old newsletters — yet the account still uses much more storage than expected. The reason may be duplicate emails. Mail migrations, server changes, antivirus scanners, backup restores, and synchronization problems can leave multiple copies of the same message in an IMAP mailbox. These duplicates are often difficult to notice because your email client may group or hide them. https://medium.com/@chris.ahrweiler/is-your-mailbox-full-duplicate-emails-may-be-the-reason-eec271ca9b3d