How Can We Boost Employee Engagement in Office Parties and Improve Coordination?

I am looking for suggestions on how I can motivate employees to be engaged in office parties. I often find them not responding on time to emails as well. I have shared a survey form with them but have not had fruitful results, unfortunately. While the environment of the organization is good, there seems to be a lack in coordination and engagement.

How can we work on improving the situation?

1. How many years have you been working with your current organization?

2. Why do you think employees are not motivated?

3. What type of emails do you write to employees that they are not responding to?

4. How do employees benefit from filling out the survey form?

5. What do you mean when you say 'the organization has a good environment'?

6. How did you determine that there is a lack of coordination and engagement?