For protect Zimbra Mail Server from SPAM. Zimbra have two Anti Virus is clamAV & Spam Assasin. Anti Virus Zimbra automatic update database every two hours. If the time is too fast or long, you can change update period Database by following the steps below :
- Open and Login Zimbra Admin
- Click Configure | Global Settings | AS/AV
- Input long the database updates on the Definition Update Frequency. Unit updates in hours.
Check this video for information :