I logged in as an Administrator and has a required ACLs. I am testing a document which is sent by a partner. In that document, there is a username and password. I think its causing the problem but I am not sure. I have a profile setup for this partner.
You need to make sure that the partner is setup with the proper ACL to access TN receive service. If not, you will get the error. I usually make a new group for my external partners and attach each group to the TN Partner ACL. The documentation is much clearer on this. I don’t have the docs in front of me right now. HTH