No one has a duty to leave feedback. It's entirely voluntary. That being said, most sellers leave feedback but fewer than half of buyers do.
You've left 215 feedbacks but have received 241, so you have not left feedback for all of your trading partners either.
It's considered bad form to send feedback reminders, so I would advise against it. Members will either leave feedback or they won't. If they are not inclined to, a reminder is annoying. If they are inclined to but just haven't left it yet, a reminder is annoying. Members have 60 days to leave feedback.
Inceptions
Volunteer Community Mentor, buying and selling on eBay since 2004
