Steps to switch the zimbra webmail from Classic to Modern UI

Step 1: Login to  your webmail > Click on gear icon in the upper right corner

Step 2: Select the Modern UI.

Step 3: The Modern Webmail will appear

Step 4: Once you switch to Modern UI you will have some new icons like mail, Calendar and Briefcase , Chat , Cloud Storage and Contacts.

Step 5: To find the other options like Signatures, Accounts, Filters, Blocked and Allowed Senders, click on the settings option in the upper right corner

Step 6: Now you will view the other options