Best Postaci Alternatives & Competitors in 2024

Web-based IMAP email client

Open Source

RainLoop is a web based email client.

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)

Horde Groupware is a free, enterprise ready, browser based collaboration suite.

All your E-mail, from all your accounts, in one place. Cypht is like a news reader, but for E-mail.

Open Source

Mailpile is a modern, fast web-mail client with user-friendly encryption and privacy features.

Open Source

Open Source WebMail Lite is a free community edition of full-featured WebMail Pro server applicatio...

SquirrelMail is a standards-based webmail package written in PHP.

Open Source

Zimbra is trusted by over 500 million users to increase productivity with a complete set of collaboration tools while maintaining total control over security and privacy.

A fully fledged, free email server solution, an open source project (GPL v2).

Open Source

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

Save time and scale faster with accessible, secure, and reliable cloud email services. A proven multitenant email solution for telcos and service providers.

freemium $1.3 / Monthly (Per mailbox)

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

Open-Xchange Server 6 is the most advanced Linux based Groupware solution f.