Company branded Private Email Networks (PENs) can be configured to preemptively filter out messages containing inappropriate key strings of text (e.g. racial slurs, sexually inappropriate language, impolite or vulgar words). These email2 messages are never delivered, and an administrator is notified of the incident. This helps to contain incidents and is an effective risk management tool. Filtering can also prevent offensive inbound messages from being retrieved.

PENs are also able to block communication with inappropriate domains (e-mail addresses). This could include competing companies, or in the case of a private company PEN, simply any e-mail addresses not associated with the company. PENs can be configured so that users are only able to communicate with people in a pre-defined list (black and white listing).

In addition, a properly configured PEN is able to silently monitor communication between users when a filter determines that it contains certain key words or phrases. This is a useful records-keeping tool should the records ever be required for litigation or an audit.

//Edited June 2009