Best Polymail Alternatives & Competitors in 2025

Airmail is a lightweight and lightning fast mail client for Mac.

Spark helps you take your inbox under control. Instantly see what’s important and quickly clean up the rest. Spark for Teams allows you to create, discuss, and share email with your colleagues

Open Source

The #1 email warming service to improve your deliverability by generating realistic and meaningful engagement to your emails. Easy-to-use solution to help you land in the main inbox instead of the spam folder.

Visit website paid $19.5 / Monthly (Pro)

Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!

Mailbird is the best email client for Windows 7, 8 and 10

Gmail is available across all your devices Android, iOS, and desktop devices. Sort, collaborate or call a friend without leaving your inbox.

Privacy-aware email app for Mac & iOS

Email at its best, new from Basecamp.

paid Free Trial $99.0 / Annually

eM Client is a fully-featured email client for Windows and macOS with a clean and easy-to-use interface. eM Client also offers features for calendars, tasks, contacts, notes, and chat.

freemium

At Mixmax, our mission is to change how the world communicates. We’re an email productivity platform that helps sales, customer success, and recruiting teams do their jobs better.

There’s big news attached.

The Power Email App for busy professionals, like you.

The Nylas Cloud API powers your application with email, calendar & contacts features. Built-in features for better email, calendar, and contact management.

Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.