The Attachments tab can be configured with global rules to reject mail with files attached, and to disable viewing files attached to mail messages in users’ mailboxes. When attachment settings are configured in Global Settings, the global rule takes precedence over COS and Account settings.
The attachment settings are as follows:
Attachments cannot be viewed regardless of COS. Users cannot view any attachments. This global setting can be set to prevent a virus outbreak from attachments, as no mail attachments can be opened.
Attachments are viewed according to COS. This global settings states the COS sets the rules for how email attachments are viewed.
Reject messages with attachment extension lets you select which file types are unauthorized for all accounts. The most common extensions are listed. You can also add different extension types to the list. Messages with those type of files attached are rejected and the sender gets a bounce notice. The recipient does not get the mail message and is not notified.
Note: Attachments settings can also be set for a Class of Service (COS) and for accounts.
To temporarily block message delivery to an account, you can change the account status to "maintenance".
To temporarily block message delivery for all accounts on a particular Zimbra mail server, you can stop mailbox service on that host. Mail will be queued at the MTA until mailbox service is resumed.