When comparing Opera Mail vs Canary Mail, the Slant community recommends Canary Mail for most people. In the question“What are the best e-mail clients for macOS?” Canary Mail is ranked 6th while Opera Mail is ranked 11th.
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 Pretty Good Privacy or PGP built-in
Pro Gorgeous and intuitive
Pro No personal data stored on servers
No access tokens, passwords, attachments or email itself is stored on Canary servers.
Pro Local email database is encrypted on disk
Canary stores your local email database encrypted.
Con Very limited feature set
Compared to Thunderbird.
Con Does not support 4K monitors
Con Sync is slow
Opera tends to be slower on e-mail sync when compared to other popular clients.
Con Poor text editing capabilities
The cursor is laggy so you're better off using keyboard shortcuts.
Con Windows moves randomly
When you create a new email, the new windows is often misplaced so that you have to move it to reach the "Send" button.
Con Poor handling of new emails
You sometimes need to wait very long before your email actually gets delivered.
Con Show NO show
It'll show I have new email as a counter but I'm not able to view them.