Zimbra Desktop vs. Missive

Zimbra Desktop is a free and open source email client application that gives you online and offline access to all your email accounts in one place. Zimbra Desktop works with many types of email systems to synchronize email, contacts and calendar data between users mailboxes in the cloud and local data stored on your computer disk.

Are you double sending emails? Not knowing who's responding to what, or whether they've responded at all? Losing the thread when the person who owns it is out? What if your business could manage all your email accounts, including its shared inboxes like support@, sales@, info@, and accounting@, along with SMS, WhatsApp, Messenger, and Instagram—all in one place? Missive is inbox collaboration for teams that run on email. Every conversation gets an owner, so nobody replies twice and nothing sits unread for a week.