The best way to ensure all your data and settings are brought over is through Backup and Restore.

Follow these steps:

In the old device:

1.        Create a backup through Menu > Backup (Menu > File > Backup in eM Client 7 and older)
2.        Deactivate your license if you are no longer going to use eM Client on this device in Menu > Help > License (not needed for one-seat licenses, but useful for making sure no licensing problems happen)
3.        Find the .ZIP backup file and move it to your new device
   (by default in ..\Documents\eM Client)

In your new device:

1.        Install eM Client (download it here)
2.        Skip initial setup
3.        Restore from your backup through Menu > File > Restore
4.        Activate your license in Menu > Help > License

If you put the backup file in the new device in the same folder structure as the default (..\Documents\eM Client) the restore will find it right away. Otherwise, you'll need to specify the path where the backup file can be found (in Menu > Settings > General > Backup).

You can also find these steps in our blog here: New device and eM Client? No problem!