Mobile web browser
Accessing Zimbra through a Mobile Web Browser
To use the Zimbra Mobile Web Client, open the HTML-compatible browser on your phone and type in the same URL that you do to access Zimbra in a desktop web browser then add /m/ at the end of the URL.
Be sure to double check if you need to use "http://" or "https://".
At the right you see the resulting log in page, which is the Zimbra Collaboration Suite but defaulted to "mobile" access mode.