Need OOB API for uploading and downloading file for external/internal partners in SFG

There are multiple APIs available in B2Bi, but as confirmed by the support team(TS021932486,TS01932439), these APIs are intended only for internal use. Currently, there is no out-of-the-box API available for external partners to directly upload or download files from their mailbox using REST APIs.

This is one of the most common customer requirements, where partners expect simple REST-based APIs for file upload and download operations. Given the growing adoption of API-driven integrations, this is a capability we expect to have as a standard out-of-the-box feature.

At present, the available workaround is to create custom HTTP Server Adapters with dedicated URIs that invoke custom business processes to perform mailbox operations. While this approach works, it has several limitations:

• It only supports Basic Authentication, which is a major security concern for many organizations.
• It introduces additional implementation complexity by requiring custom business processes.
• It can create unnecessary performance overhead by relying on HTTP services and business process execution for simple file operations.

The product should provide standard out-of-the-box REST APIs for common mailbox operations such as:

• Listing available messages/files in a mailbox
• Downloading files individually or in bulk
• Uploading files directly to a mailbox with a simple payload submission
• Deleting or managing mailbox content as required

This would simplify customer implementations, improve security by supporting modern authentication mechanisms (OAuth, token-based auth, mTLS, etc.), and reduce dependency on custom solutions for a very common use case.