Opera's recent transition to to Chromium and Blink resulted in the underdog web browser losing its integrated email client. Although longtime users may see that as a step in the wrong direction, today the Norweigan company is offering a standalone client as a replacement, which is touted as lightweight and fast.
Opera Mail features a tabbed interface so users can have multiple items open at the same time and switch back and forth between them. Although definitely not the first to implement this, it certainly streamlines getting work done, as being able to jump around without closing tabs can be quite convenient.
Another interesting design choice in Opera Mail is the way it organizes conversations. The software creates threads of all conversations in which a user is involved, with the option to unfollow one when it no longer seems relevant. When those giant chains of email get out of control, this feature should be nice, either for keeping the conversation organized or for unsubscribing from the email thread altogether.
The company also built a deep system of filters and labels into the mail client to help you keep things organized.
While Opera did a good job with Opera Mail it seems that less and less people are relying on dedicated email clients clients nowadays, opting to use a standard web-based interface instead. Integrating it into the browser might have represented a fair middle ground between both approaches.
If you are among those that still swear by desktop email clients be sure to check it out.
Download: Opera Mail for Windows and OS X