There are many of the best IMAP email backup tools. I can suggest the best tool because I'm also using it. Try the TrustVare IMAP Backup Tool, which can securely backup IMAP emails without any issues. It allows users to download and save complete mailbox data, including emails, attachments, and folder structure, without any data loss. The software maintains original formatting and hierarchy during the backup process, ensuring data integrity. It has a simple interface that allows non-technical users and they can use it without technical skills. It will work on all Windows OS versions like 11, 10, 8.1,8, and 7 without downloading any application.