US 11,856,001 B2
Method for securely communicating email content between a sender and a recipient
Hoala Greevy, San Francisco, CA (US)
Assigned to Paubox, Inc., San Francisco, CA (US)
Filed by Paubox, Inc., San Francisco, CA (US)
Filed on Jun. 16, 2022, as Appl. No. 17/842,347.
Application 17/842,347 is a continuation of application No. 17/014,905, filed on Sep. 8, 2020, granted, now 11,399,032.
Application 17/014,905 is a continuation of application No. 15/683,246, filed on Aug. 22, 2017, granted, now 10,805,311, issued on Oct. 13, 2020.
Claims priority of provisional application 62/378,068, filed on Aug. 22, 2016.
Prior Publication US 2022/0321577 A1, Oct. 6, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H04L 9/40 (2022.01); H04L 51/212 (2022.01)
CPC H04L 63/123 (2013.01) [H04L 51/212 (2022.05); H04L 63/0236 (2013.01); H04L 63/0281 (2013.01); H04L 63/0428 (2013.01); H04L 63/1408 (2013.01); H04L 63/168 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for end-to-end encryption of electronic mail comprising:
receiving a first email encrypted according to a first encryption protocol, the first email sent by a sender at a first domain and designating a first recipient address at a second domain;
in response to a recipient exclusion list including the first recipient address:
accessing a first set of encryption protocols supported by a first recipient mail client at the first recipient address;
encrypting the first email according to a second encryption protocol, in the first set of encryption protocols, less robust than the first encryption protocol; and
transmitting the first email, encrypted according to the second encryption protocol, to the first recipient address; and
receiving a second email encrypted according to a third encryption protocol, the second email sent by the sender at the first domain and designating a second recipient address at a third domain; and
in response to the recipient exclusion list excluding the second recipient address:
accessing a second set of encryption protocols supported by a second recipient mail client at the second recipient address;
in response to the second set of encryption protocols excluding the third encryption protocol:
generating a notification email comprising a link to a webpage containing content of the second email; and
transmitting the notification email to the second recipient address; and
in response to selection of the link at the second recipient mail client executing on a computing device, serving the webpage containing content of the second email to a web browser executing on the computing device.