Explanation
Web mail, Instant Messaging and personal networking sites are some of the most common means by which corporate data is leaked.
Data loss prevention (DLP) is a strategy for making sure that end users do not send sensitive or critical information outside the corporate network. The term is also used to describe software products that help a network administrator control what data end users can transfer.
DLP software products use business rules to classify and protect confidential and critical information so that unauthorized end users cannot accidentally or maliciously share data whose disclosure could put the organization at risk. For example, if an employee tried to forward a business email outside the corporate domain or upload a corporate file to a consumer cloud storage service like Dropbox, the employee would be denied permission.
Full-tunnel VPN should be required for all network communication. This will ensure that all data transmitted over the network is encrypted which would prevent a malicious user accessing the data by using packet sniffing.

Network logging tools such as Syslog, DNS, NetFlow, behavior analytics, IP reputation, honeypots, and DLP solutions provide visibility into the entire infrastructure. This visibility is important because signature-based systems are no longer sufficient for identifying the advanced attacker that relies heavily on custom malware and zero-day exploits. Having knowledge of each host's communications, protocols, and traffic volumes as well as the content of the data in question is key to identifying zero-day and APT (advance persistent threat) malware and agents.
Data intelligence allows forensic analysis to identify anomalous or suspicious communications by comparing suspected traffic patterns against normal data communication behavioral baselines.
Automated network intelligence and next-generation live forensics provide insight into network events and rely on analytical decisions based on known vs. unknown behavior taking place within a corporate network.

Explanation
A request for a Proposal (RFP) is in essence an invitation that you present to vendors asking them to submit proposals on a specific commodity or service. This should be evaluated, then the product should be tested and then a product recommendation can be made to achieve the desired outcome.