For a quick and reliable solution, I would recommend the
CloudXena IMAP Email Backup Tool. This utility can migrate your IMAP file to different file formats such as PST, PDF, MBOX, EML, MSG, CSV, DOC, and DOCX. Also, it can export IMAP Email to Gmail, G Suite or Google Workspace, Thunderbird, etc. By using this tool, you can use advanced features like Bulk Data Migration and Eliminate Duplicate Emails.
Here are simple steps to backup IMAP Emails:
1. Open and launch the CloudXena IMAP Email Backup Tool on your computer.
2. Log in to your IMAP email account and click Sign In.
3. Choose the email folder you want to back up, then click Next.
4. From the drop-down list, pick PDF or PST as the file type.
5. Select a folder on your computer to save the file.
6. Click the Convert button to start the backup process.