RMail® and RSign® are integrated into Zimbra using the Zimlet structure. The RMail for Zimba add-in preserves the native functionality of Zimbra and the outbound SMTP message stream. The RMail large file transfer services use RMail REST API. RSign is connected to Zimbra using REST API.
Each e-sign completion and each message sent return the final Registered Receipt™ and e-sign records into the Zimbra Inbox (into auto-generated receipt and contracts folders). These include delivery and e-sign forensics, cryptographically sealed to the delivery content and timestamp, and packaged as a Registered Receipt™ proof record or a signature certificate record.