This article outlines whether an eBay Integration exists for Kayako.
There is no integration with eBay due to some limitation.
The usual request is that when a customer submits a question on eBay and then create a conversation on Kayako. Then the agents can then respond from Kayako.
There is a limitation in that Kayako will only create the ticket for the eBay account. The actual customer’s email address is not part of the communication.
So when an agent responds from Kayako, the customer will never get the response.