How does/does not relaying all outgoing mail from one's mail server to
an SMTP "smart host" at one's ISP for them to deliver remotely, rather
than delivering all messages end-to-end directly from one's own mail
server to remote servers, affect legal and regulatory archiving
requirements such as SEC 17a, et al.?  Can the ISP's mail server be
considered a part of your "system," since the mail has to either be
within the sender's boundaries or the recipient's, and is there a
possibility that statutes/regs would thus extend to them?