Postbox Alternatives [Page 2]

Claws Mail is an email client (and news reader), based on GTK+, featuring Quick response

Sylpheed is a simple, lightweight but featureful, and easy-to-use e-mail client (mailer, MUA).

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)

Privacy-aware email app for Mac & iOS

Unibox is an application that aims to completely overhaul your email experience. Unibox resorts your email so that you can group the messages you receive by their sender. Read more about Unibox.

K-9 is an opensource email client making it easy to chew through large volumes of email.

MailMate is an alternative email client that was designed for the macOS.

Inky is a software program that roots our phishing emails to better your cybersecurity.

Native email app for email productivity.

The perfect mail merge tool for Gmail

We make the send button safer. For every campaign, every message, and every inbox, Email on Acid has the time-saving tools you need to put your best email forward.

paid Free Trial $73.0 / Monthly (With a year subscription)

Mail-in-a-Box provides webmail and an IMAP/SMTP server for use with mobile devices and desktop mail software and also includes contacts and calendar synchronization.

Open Source

Shift is the ultimate email client for managing Mail, Calendar, Drive, Slack, Asana, Jira, Evernote, and all your other favourite apps

freemium

Interseller helps find contact information, reach out to them with email automation and syncs it all into your database.