MailSentinel allows organizations to manage productivity of the enterprise, preserve network bandwidth and reduce legal liability through controlled e-mail access. MailSentinel is powerful security tool to protect your company from unwanted correspondence in company. Some of MailSentinel features include: Blocking of undesirable domain-receivers. Forcing authentication of E-mail senders.Checking logon access rights of E-mail users. Loging outgoing e-mails. Shareware: $50-$200.