Backing up emails from an IMAP mail server depends on your preferred method and technical expertise. Here are two common approaches:

1. Using your email client:

• Microsoft Outlook: If you use Outlook with your IMAP account, you can export your mailbox data to a PST file. This file format stores emails, contacts, and calendars locally on your computer.
• Other email clients: Many email clients offer similar export functionalities. Check your specific client's settings for options to export or backup your email data.

2. Using dedicated backup tools:

• Third-party software: Several dedicated applications specialize in backing up email from IMAP servers. These tools often offer more flexibility and advanced features compared to built-in client options. They allow you to choose specific folders or emails to backup, select the desired file format, and schedule automated backups.
  
• Shoviv IMAP Backup Tool

Additional considerations:

• Security: When using third-party tools, ensure they have a good reputation and secure data handling practices. Never share your email login credentials with untrusted applications.
• File format: Choose a backup format compatible with your needs. PST is common for Outlook users, while other formats like EML or MBOX might suit broader uses.
• Storage location: Store your backups on a reliable external storage device or cloud storage service to prevent data loss in case of local hardware failure.

Remember, the best approach depends on your individual needs and comfort level with technology. Consider researching different options and choosing the method that best suits your specific situation.