Frequently Asked Question

Zimbra handles spam and malware protection through standard anti-spam packages, internal throttling mechanism as well as allowing integration with other tools.

• Spam and Virus – Zimbra uses standard packages – Spamassassin and Amavis to make sure the emails are free of virus and are not spam emails.
• DoSFilter Throttling Mechanism – Ability to throttle clients sending a large number of requests over a period of time. By using http(s) protocol, it can set rate limit per second and institute a delay of breach of limit. It can also provide whitelisting capabilities of IPs with CIDR notation.
• Cluebrinder Policy Daemon (CBPolicyD) – Implemented as part of the Zimbra MTA package. CBPolicyD is a policy server that provides Access Control, HELO/EHLO checks, SPF checks, Greylisting, Time-based Quota enforcement, Time-based message accounting and size tracking as well as sender and recipient accounting, including Amavis integration.