The Email Security Gateway (ESG) services has a number of layers and engines to determine if inbound mail is SPAM, contains a virus/ malware or other suspicious attachments or is part of a phishing campaign.

Each of the engines performs a different function and an email is allowed, denied or the subject modified according to these process outcomes.

The following diagram outlines the decision tree and data flow associated with each of the engines and how an email may or may not be quarantined by the ESG.

When an email flows through the decision tree email subjects will be prefixed with an attack type (or engine outcome). For example, if someone sends an email with the subject "50% off website SEO" that is determined to possibly be spam the subject will read "[SISSESG: Probable spam email] 50% off website SEO"

To provide our uses with the applicable policy and associated text, please refer to the following tables.

Anti-Spam

Anti-Virus

Anti-Phishing

Content Filtering

An example of the email messages follows

Scan Status Alert (as per "Delete email and backup" above) an email will be sent to the user to notify them of the deletion.

The following screen-shot displays an example of an email that has failed two checks with the subject line adjusted accordingly.