The default global setting for attachment viewing is to let users view attachments to their email according to the COS assigned to the account. The COS default setting allows users to view attachments in their original format.
To view attachments in the original format, users must have the corresponding application installed on their computer. This might not always be the best option.
Zimbra Collaboration Server offers the following options to view attachments:
Disable attachment viewing from web mail UI. Users cannot view any attachments.
Attachments may be viewed in HTML only. Email attachments can only be viewed in HTML.
Attachments may be viewed in their original format only. Users must have the corresponding application on their computer to view the attachment.
Attachments may be viewed in HTML and their original format. Users are given the option to either open it in the original format or to view the attachment in HTML.
-------------------------------------------------------------------------------------------------------
Copyright @ 2005-2017 Synacor, Inc. All rights reserved. "Zimbra" is a registered trademark of Synacor, Inc.