What makes you respond to emails?

Not even just cold emails but like, any emails.

I feel like I send out so many emails for so many different reasons, and they always get ghosted even after follow ups. What can I do to make people respond?

And yes, I realize I am in no way entitled to your time. Yall are busy as hell I get it honestly. But still, a quick response to questions at least would be very nice ;-;