Transfer from PC to MAC

Can em Client emails and contacts be transferred from a W10 PC to a Mac Air laptop?

Yes, there are a couple of options.

  1. If your contacts and messages are synced with a server, that means you can see them in eM Client, but also when you use the web interface for your email provider, then setting up the same account on the Mac will sync the contacts and messages there as well.

  2. If your contacts and messages are not synced with a server, you can export them from eM Client on the PC and import them into eM Client on the Mac.

If you just want to move eM Client completely from the PC to the Mac, or duplicate it on the Mac, see this article:

How to move my data to a new computer?