Abstract: A mail inserter having an insertion station for inserting mailing material into an envelope. The mail inserter further comprises a sheet provider module for providing sheets of mailing material, an exit module for conveying the mailing material to the insertion station, and an intermediate module, which can be a sheet folder or a sheet transport disposed between the sheet provider module and the exit module. The sheet provider can be a cut sheet feeder or a burster for separating individual sheets from a continuous web. The sheet provider and the burster are mechanically interchangeable. The folder and the sheet transport are also mechanically interchangeable. The exit module can additionally has a trap stage to temporarily hold the mailing material until the insertion station is ready to receive the next mailing material, and a slitter to trim off an edge of the mailing material.