Platform as a service (PAAS) featuring computer software platforms for providing an email client that (a) reduces junk email, (b) assists in unsubscribing, and (c) displays inbox advertising, to thereby (i) track and reduce carbon footprint or (ii) plant trees based on inbox advertising; Providing a web site featuring technology that enables users to access an email client that (a) reduces junk email, (b) assists in unsubscribing, and (c) displays inbox advertising, to thereby (i) track and reduce carbon footprint or (ii) plant trees based on inbox advertising; Providing temporary use of non-downloadable cloud-based software for providing an email client that (a) reduces junk email, (b) assists in unsubscribing, and (c) displays inbox advertising, to thereby (i) track and reduce carbon footprint or (ii) plant trees based on inbox advertising; Software as a service (SAAS) services featuring software for providing an email client that (a) reduces junk email, (b) assists in unsubscribing, and (c) displays inbox advertising, to thereby (i) track and reduce carbon footprint or (ii) plant trees based on inbox advertising