Automator Workflow Warning

Please help.

I have an iMac, and I want to copy all my Mail Library to my MacBook Pro Mail Library. Kind of a backup, but I want to do it to have all the subfolders created on Mail on my iMac as well as on my MacBook Pro. I know Exchange Server is the solution but I don't have the $$ to buy it right now.

I have tried to do it using Automator like this

Find Finder Items (completed)

Copy Finder Items (completed with 1 warning "The action "Copy Finder items" was not supplied with the required data") 😕

Is there a better /easy way to do it?

What am I doing wrong?

Thank you for your support.