When comparing Unibox vs Newton, the Slant community recommends Newton for most people. In the question“What are the best e-mail clients for macOS?” Newton is ranked 11th while Unibox is ranked 13th. The most important reason people chose Newton is:
Newton grabs information from LinkedIn, Facebook, and Twitter accounts linked to the sender's email address. It then displays information which can help you figure out who the emailer is, such as their job title and where they work.
Specs
Question Ranking
Pros
Pro Simple, clean interface
Unibox's interface is very clean and easy to understand. It has a classic two-pane interface with all users that have sent emails on the left side and any email currently being read on the right.
Every UI element is only visible when needed. For example, every time you hover on a discussion the trash can, which is otherwise invisible appears.
Pro All emails are sorted by contact
Pro Makes it easy to keep track of different discussions
Unibox groups different emails by user instead of subject. This makes it easy to keep track of messages sent to a particular person and to keep track of different discussions.
Pro Know who's emailing you
Newton grabs information from LinkedIn, Facebook, and Twitter accounts linked to the sender's email address. It then displays information which can help you figure out who the emailer is, such as their job title and where they work.
Pro Snooze incoming emails
You can snooze emails to come back at a convenient time - whether it be in 2 hours, or next Wednesday.
Pro Works across multiple platforms
While there is no Windows app, Newton is available on iOS, Android, and macOS, including Android Wear and Apple Watch.
Pro Logs messages to Salesforce
Cons
Con Sends empty emails
Other than syncing issues and displaying wrong badge numbers, Unibox sometimes sends empty emails to people in the user's contact list, which is quite annoying.
Con A number of recurring issues
There are some recurring issues with Unibox: these include the sync dropping and e-mails not reaching their destination.
Con Always needing to update token for Gmail
Con Subscription based
Newton costs $49.99 per year after the 14 day free trial.