When comparing Opera Mail vs Newton, the Slant community recommends Opera Mail for most people. In the question“What are the best e-mail clients for macOS?” Opera Mail is ranked 7th while Newton is ranked 14th.
Ranked in these QuestionsQuestion Ranking
Pro Opera Mail CAN BE set as default email client in Windows 8 & 10
Pro Automagic smart filtering
After a bit of use Opera learns what e-mail belongs in what folder just by previous usage. This makes for a convenient way to have e-mails filtered without having to manually mange every e-mail.
Pro Free and based on Mozilla code
Opera Mail is completely free to download and use and it is based on Mozilla's code, which is what makes it a bit similar to Thunderbird in looks and function.
Pro Intuitive user interface
The design of the UI in Opera Mail is clean and intuitive, making for an easy to use client.
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 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.
Con Sync is slow
Opera tends to be slower on e-mail sync when compared to other popular clients.
Con Subscription based
Newton costs $49.99 per year after the 14 day free trial.