When connecting to Zimbra from a mobile device using Google Chrome (Chrome works best with Zimbra), the default Version selected for quick emails is “Mobile” as in the first image below:

Mobile Device UNA Zimbra Mail login window (Mobile)

If you wish to access more advanced features than basic email read/sending or attaching existing emails or existing documents in a briefcase to share, Select the Advanced (AJAX) for computer desktop view when logging in from a mobile device.

Mobile Device UNA Zimbra Mail login window (Advanced)

Advanced (AJAX) will give you the full Zimbra view, however will utilize more data than the mobile view if you are not on a WiFi network.

Once connected using the Advanced (AJAX) Version, you can create a “New Message” and use the Attach button as usual in your new message to either take a new photo, or select items from your device.

If you are not attaching one of the specific documents listed (Briefcase Contacts or another Mail message), after tapping the Attach button, select “My Computer” as it indicates to Zimbra that you are selecting an image that is local to the device, or one you will be creating on the device.

If you choose, you can select items from your Photo Library, Take a new Photo or Video, or Browse your Files/Folders on the device for an attachment.

If you have Local Executive mailbox access, you will see it in the sidebar.  Read about disclosure triangles here: https://help.una.ca/zimbra-shared-mailboxes-and-disclosure-triangles/