A system and method for processing communications between a sender computing device and at least one recipient computing device are provided. A sender establishes a secure communication with a document processing server and requests the processing of an electronic document, which can include the appending of a digital signature. The document processing server processes the electronic document and establishes secure communications with one or more designated recipients. The document processing server can implement sender specified recipient identity verification and provide further processing of the electronic document as designated by the recipients.