Hoi Kristof,

Every HTTP request which are happening on the Peppol Network need first to go through an SML (https://github.com/OpenPEPPOL/documentation/blob/master/TransportInfrastructure/ICT-Transport-SML_Service_Specification-101.pdf) and then an SMP (https://github.com/OpenPEPPOL/documentation/blob/master/TransportInfrastructure/ICT-Transport-SMP_Service_Specification-110.pdf).

The Peppol Access Point are here to register you on a SML and a SMP, and Odoo is effectively mentioned in this list : https://peppol.eu/who-is-who/openpeppol-member-list-2/

I supposed that Odoo S.A can give some visibility on the status of each Peppol transaction which are done by their Odoo system but for the Community Version I do not know.

Let me know if I can bring others information.

There is the module account_invoice_ubl that does this. But it just generates UBL, not BIS standard (you could fork and update the addon if this is an option).

In case you use Odoo v12 or higher, I think this must be included by default, as Odoo is a Peppol Access Point. Please consult Odoo here.