How do I back up eM Client?

How do I back up eM Client? For example, saving my emails in case of disk crash, or migrating to a new PC.

the easiest way how to backup your data is to use built in backup feature which simply creates copy of your current database folder and saves it into your Documents. You can find it under the menu File - Backup. Afterwards, you can copy the backup file to an external drive to prevent data loss in case of disk crash.