Abstract: Techniques of peer-to-peer email synchronization are disclosed herein. In one embodiment, a technique includes transmitting, from a first client device to an email server, a synchronization request to synchronize an email between the email server and the first client device. In response, the first client device receives a reply containing data representing a replicate identification of email content of the email and identification of a second client device at which a copy of the email content is present. Upon receiving the reply, the first client device can establish a peer-to-peer communications channel with the second client device, download a copy of the email content of the email from the second client device instead of the email server, and surface the downloaded email content in an email client on the first client device to a user.