Windows/Mac: Desktop email clients aren't as popular as they used to be, but Inky brings something new to the desktop scene: a super simple interface with a focus on only the messages that matter to you.
Setting up Inky is easy. You don't need to know any complicated IMAP features to set up your accounts; you just type in your email address and password and Inky will detect what service you use. It automatically scan your contacts and messages and marks selected messages with importance labels: a dark ink drop denotes an important message (such as one received from your contacts), while lightly-coloured messages denote less important newsletters or promotions.
Inky also has a number of smart views that let you only see emails from your contacts, social sites, newsletters, and other sources at one time. It will let you unsubscribe to any newsletter with the click of a button, give you a map of any street addresses it finds, and even suggest other people you might want to include in a given message.
In short: despite its somewhat cartoony appearance, it actually has a lot of the features we've come to love from webmail clients like Gmail and Outlook.com. Is it as powerful? Not quite, but it's definitely a new approach to desktop mail clients, so if you need the advantages only a desktop client can provide, it's worth a look.