Outlook Web App is the more common of the two in our index: it runs on 19 websites against 4 for Zimbra. Counts come from real scans of each site's home page, not vendor claims, and cover the sites in TechLookup's index rather than the whole web.
Outlook on the web is an information manager web app. It includes a web-based email client, a calendar tool, a contact manager, and a task manager.
Zimbra is a provider of open-source email and collaboration software, offering solutions for email, calendar, contacts, and collaboration for both individual and enterprise use.
Within the webmail sites we have indexed, Outlook Web App holds 0.0% and Zimbra 0.0%.
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