10. A system comprising: a non-transitory memory storing collaborative email information comprising a collaborative email document; and one or more hardware processors configured to execute instructions to cause the system to perform operations comprising: generating a collaborative email document comprising metadata identifying collaborators and an administrator of the collaborative email document and an email body having editable email message text, wherein the collaborative email document identifies signatories to the collaborative email document; providing editable copies to the collaborators of the collaborative email document for viewing and editing the editable email message text of the collaborative email document, wherein the editable copies reside on devices of the collaborators; updating the editable copies of the collaborative email document on the devices of the collaborators with revisions of the editable email message text from the collaborators, wherein the updating the editable email message text occurs synchronously through an instant messaging protocol as the revisions are made, and wherein the instant messaging protocol is associated with a server that generates the collaborative email document; sending the collaborative email document with the revisions from a device of the administrator to an addressee in response to determining that the collaborative email document is digitally signed by each of the signatories; and alerting the signatories to sign the collaborative email document through the instant messaging protocol.
10. A system comprising: a non-transitory memory storing collaborative email information comprising a collaborative email document; and one or more hardware processors configured to execute instructions to cause the system to perform operations comprising: generating a collaborative email document comprising metadata identifying collaborators and an administrator of the collaborative email document and an email body having editable email message text, wherein the collaborative email document identifies signatories to the collaborative email document; providing editable copies to the collaborators of the collaborative email document for viewing and editing the editable email message text of the collaborative email document, wherein the editable copies reside on devices of the collaborators; updating the editable copies of the collaborative email document on the devices of the collaborators with revisions of the editable email message text from the collaborators, wherein the updating the editable email message text occurs synchronously through an instant messaging protocol as the revisions are made, and wherein the instant messaging protocol is associated with a server that generates the collaborative email document; sending the collaborative email document with the revisions from a device of the administrator to an addressee in response to determining that the collaborative email document is digitally signed by each of the signatories; and alerting the signatories to sign the collaborative email document through the instant messaging protocol. 12. The system of claim 10 , wherein the operations further comprise: establishing a hierarchy of delegation authority for the signatories to the collaborative email document; establishing at least one authority delegation policy comprising at least one rule for automated delegation of signature authority among the signatories in the hierarchy; and delegating the signature authority from at least one signatory to another signatory in accordance with the at least one authority delegation policy.