I hope you are well . unfortunately i have been trying to active my free license but after copying the Activation key this error is coming up: This computer cannot be activated due to violation of our licence policy
could you please assist me in this matter
It means you are using a Free license for business use. A Free license is for personal home use only, so that is a violation of the license policy you agreed to.
If you want to use eM Client with your business email, a non-profit or other organisation, etc., you will need to purchase a Pro license.