When comparing Polymail vs Yahoo! Mail, the Slant community recommends Polymail for most people. In the question“What is the best desktop Email client for Windows 10?” Polymail is ranked 14th while Yahoo! Mail is ranked 18th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro One-click unsubscribe
Pro Free tracking option
Using a tracking pixel that will allow the user to know if an email has been opened.
Pro Scheduled follow-ups
Pro Responsive dev team
Pro Viewed as the eventual successor to Mailbox
Pro Tabs
With this Yahoo! Mail feature users can open any e-mail in a new tab and get back to the mail list without having to close the e-mail that the user is currently reading.
Pro Background wallpaper
Similar to Mail app bundled in Windows 10, Yahoo! Mail allows users to set images from Flickr as the background image for the app.
Pro Stationary
Stationary is an add-on that's only available in Yahoo! Mail. It allows users to customize and enhance the look of the email. Things like image borders, letter style etc. can be changed before sending the email to intended recipients.