If you receive messages containing unknown partners, those are automatically added to the master data with the name „PLEASE COMPLETE PARTNER MASTER DATA“ to the unknown corporation „?“ You just have to complete the information by adding name, address, etc to the partner and to add it to the correct corporation. Unless you've done this, you won't be able to create other messages from this one or use the partner in another message.

The buyer is not automatically inserted, because he always must be known.