You can deploy Symantec Messaging Gateway very easily on-premise. Security configuration is very easy and web GUI is very user-friendly. You can access any configuration parameters with a web interface. Symantec catches more than 99 percent of spam with a less than one in one million false positives, so its spam catch rate is very high. You can create a custom policy for detailed email control. You can give your users access to their spam mail optionally. You can upgrade to new releases easily. You can schedule backup and restore configuration with one click. It allows integration with other software for security checks. Review collected by and hosted on G2.com.

Symantec Messaging Gateway's all features are best except the high availability part, I dislike its high availability feature. Review collected by and hosted on G2.com.