The Zimbra Collaboration Suite comes out-of-the-box with antispam and antivirus software, specifically, Spam Assassin and ClamAV.

In our shared hosting environment, 01.com has replaced Zimbra's built-in system, and is using dedicated, load-balanced versions of Defender MX and its extension Barricade, running from within our hosted blade-server environment. For more detailed information about the software, please visit http://www.fsl.com/

Spam is marked as Spam in the subject line of inbound email that appears to be spam, like this: [Spam].  Additionally, this spam is then placed into the Zimbra Junk mailbox for your review.  If you use a mail client, such as Mail.app, Outlook or Thunderbird among others, the Zimbra Junk mailbox will also sync to your mail client, so you can see what's been identified in your mail client, too.  Furthermore, it is straight-forward to set the Zimbra Junk mailbox as the default Junk mailbox for your mail client, for example, in Mail.app you use the Mailbox pull down menu to select Use This Mailbox For > Junk.  Viruses are disinfected if possible, and users are notified that the virus has been quarantined with a message including [Virus] in the subject.

The 01.com AS/AV system provides a secure, separate web site for clients to access using their zimbra email address and password. As indicated above, Virus-bearing emails are quarantined here, and an email notification is sent to each user when an email is quarantined. 

Clients with domain administrator privileges have control over the spam/virus filter for their entire domain, and each individual person within a given domain may just login using their email address and password, without any further configuration on the domain administrator's part, to manage their own individual and discrete preferences. Clients can check their quarantine as far back as 30 days, release items with from quarantine (in part or whole), mark items as Ham (not Spam), set general personal spam filtering levels, and add/delete white (always accept from) and black (always deny from) lists.

While we have turned Zimbra's built-in spam and virus filters off in our shared environment because the task is being managed by our dedicated anti-spam and anti-virus servers, clients may still identify spam and ham from within the Zimbra web interface, as we have configured our spam filter to add spam identified by clients to its server-wide learning routines.

Our customized, enterprise system has resulted in anti-virus filtering better than 99%, and anti-spam filtering of about 99%. Clients gain access to the 01.com AS/AV system automatically during the sign-up process. Because we hate spam, all customers are given access to the most advanced anti-spam/anti-virus feature-set available without additional charge.

Every person with a mailbox on the 01.com Zimbra servers has access to their own, personal Spam and Virus filtering preferences, including black lists, white lists and quarantine, where mail identified as spam or infected is stored for 30 days, and may be reviewed and allowed through in-whole or in- part. Additionally, users promoted to Zimbra domain administrator, which can be done independently by clients during mailbox creation, is also automatically given privileges to help control the anti-spam and virus filtering for the entire domain. Optionally, out-bound filtering rules may also be applied.

Note we also support the extra protection provided for customers by your adding a correct SPF record to the DNS for your internet domain name.