Mail Pilot is an email client that introduced new perspectives and useful features to email in 2012, such as reminders, which was later adopted by other apps as "snooze". After a record-breaking Kickstarter campaign, Mail Pilot went on to become the #1 paid app in the Mac App Store at launch. It is available today as a native app for macOS, iPadOS, and iOS.
Throttle is a service that introduced sender-specific addresses in 2015 to give email receivers fine-grained oversight and control over the transactional and bulk email headed their way, and is often turned to as a home away from the inbox for less urgent email.