You have passed a project to another person, but questions keep arriving as though you still own it. Some follow-up is reasonable. An open-ended handover makes it hard to tell when a question has become a new request for work.
Write a short account of the current position. Include the last decision, the location of the working files and the next deadline. Name the new owner and the date on which they take responsibility. Check that they have the access needed to begin.
Allow for a defined overlap
Offer a period for questions if that fits the arrangement: "I can answer handover questions until Friday." Say where those questions should go, particularly when several people are involved. The overlap should have an end that everyone can see.
After that date, direct new decisions to the current owner. You can still answer a factual question about earlier work when you choose. If the new owner needs ongoing help, discuss that as a separate commitment with its own time and scope.
