Email is personal, and some email clients allow you to install widgets or plugins that can extend the core functionality, enabling you to create a very custom application that meets your specific email needs on any device.
Many emails you receive have a task associated with them or a file you need to save for later, so it makes sense that you should be able to link that email message to your task management system (like Things 3, our favorite GTD app) or a cloud storage solution like iCloud, Dropbox, or Google Drive.
Update Schedule - The email client you use should have a track record of being well-supported to minimize the risk of it suddenly disappearing, forcing you to figure out a new tool for your email workflow.These shortcuts can be a game-changer for how you read and respond to email, so it’s important that the best third-party email client for Mac support these.
For example, to archive a message in Gmail, you just have to press the “e” key, compared to using “Shift + Command + A” in Mail.app (you can view a complete list of Gmail keyboard shortcuts by pressing “?” in Gmail).
If an email client doesn’t support your email provider, then it’s just not an option for you - no matter how awesome it looks.
It can be buggy, occasionally has issues playing nice with Gmail, and lacks some more advanced features that are present (and have been present for years) in other third-party email clients. While Mail.app provides a free, full-featured email client on every Mac and has even pioneered some innovative features over the years (like VIP and Handoff), it’s definitely not for everyone. The Mac’s default Mail application (also referred to as “Mail.app” or “Apple Mail”) has a somewhat checkered past.