Writing a collaborative email document with hierarchical authorities including establishing a collaborative email document on an administrator's computer, identifying one or more signatories for the document, identifying one or more collaborators who are authorized to view and edit the document, providing to the collaborators copies of the document for viewing and editing, where the collaborators' copies reside on collaborators' computers, updating the copies of the document on collaborators' computers with revisions from the collaborators, and sending the collaborative email document from the administrator's computer to addressees when the document bears valid digital signatures from all signatories. Typical embodiments also include providing at least one user authority to delegate signature authority, establishing a hierarchy of delegation authority for signatures, establishing at least one authority delegation policy including at least one rule for automated delegation of signature authority among signatories and delegating signature authority from at least one signatory to another.