Just wanted to add this also,


The anti-spam engine includes a regional rules profile. The regional rules profile targets spam on a regional basis. For example, China and Taiwan receive a high percentage of spam in traditional or modern Chinese. The Chinese regional rules are optimized for this type of spam. IronPort strongly recommends you use the Chinese regional rules profile if you receive mail primarily for mainland China, Taiwan, and Hong Kong.

You can enable the regional rules profile from Security Services > IronPort Anti-Spam.


Note — Because this feature optimizes the anti-spam engine for a particular region, it can reduce capture rates for other types of spam. Therefore, IronPort recommends you enable this feature only if you receive the bulk of your email from the specified region.


IronPort Anti-Spam leverages globally representative email and web content-agnostic data contributed by over 125,000 ISPs, universities and corporations throughout the Americas, Europe, and Asia. The Threat Operations Center is set up for global operations with centers in Sao Paulo, Beijing and London. In addition, analysts speak 32 languages including Chinese, Japanese, Korean, Portuguese, and Spanish.

Hi,
In release notes of 5.1.0 version we see: 
" 3. Enhancement: IronPort Anti-Spam Filtering -- Regional Rule sets"
Where we can find more information about Regional Scanning ?
If anyone already tried to set Regional Scanning to "On" ?

Thanks, Igor