B2B using EDI

Hi

Suppose if I got to post a idoc to a business partner who uses EDI system then how to proceed in this situation ? I am using XI as a integration medium.

1. whether one EDI adapter (e.g seeburger) is on receiving side is sufficient in this case ??

2. Is EDI mapper is needed in this case ?? Because message is going to convert in EDI format after mapping only..i.e after receiver adapter.

thanks

kumar