When comparing Postbox vs Opera Mail, the Slant community recommends Postbox for most people. In the question“What are the best e-mail clients for Windows?” Postbox is ranked 9th while Opera Mail is ranked 13th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Clear interface
Pro Forgotten attachment reminders by default
Reminding the user that they forgot to attach the file if they mentioned one in the body of the email is one of the most useful features of any email client and so many don't include this. Postbox is pre-configured to look for certain keywords (attached, CV, spreadsheet, pdf etc) and you can specify your own keywords in addition.
Pro Blocks tracking gifs
Has the ability to block tracking gifs commonly used for read receipts.
Pro One Inbox for all accounts
All messages in one place. But you can select to show only messages from each account either.
Pro Quick Bar for macros
Quick bar allows you to add a variety of content to your message. It will let you reuse URLS in your Sent folder, and autocompletes against canned responses, signatures, and topics.
Pro Intuitive user interface
The design of the UI in Opera Mail is clean and intuitive, making for an easy to use client.
Pro Very efficient search
Be it the subject or the sender, it is very fast and accurate.
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.
Cons
Con No support forum
Support for paid product has no online forums.
Con Being discontinued
Opera Mail will be end of lifed per Opera website
Con Very limited feature set
Compared to Thunderbird.
Con Sync is slow
Opera tends to be slower on e-mail sync when compared to other popular clients.
Con Does not support 4K monitors
