Your team produces a potentially shippable product increment at the end of each sprint. Whether this is then subjected to acceptance tests and actually being released is up to the client.
Of course, you split the big feature into product backlog items that can be handled within the Scrum framework so that it will take several sprints until it is completed, but the client may choose not to start acceptance tests before the feature as a whole is available.
The situation is similar to the starting phase of a project. Nobody expects your team to have a complete product fulfilling all requirements by the end of sprint 1 or 2. Users may experiment with whatever increments are produced during each sprint, but acceptance tests for a first release might only be started when the product is actually able to fulfill a reasonable part of the given requirements.