Sendmail's Sentrion DS 3.0 is a rack-mounted email authentication appliance used strictly for applying digital signatures to outbound emails. Deployed as a "last hop" gateway device, Sentrion uses domain keys identified mail (DKIM) to sign all messages.
The appliance was very easy to put into our test environment. We were able to power the device and configure basic settings in minutes. Configuration can be done either via command line or a cross-over cable for initial setup and then through a secured web-browser connection.
Performance-wise, this is definitely a specialty appliance. The horsepower of the server is needed because of the sheer volume of enterprise emails it may encounter. Because the device specifically signs all outbound messages using DKIM, the overhead in terms of processing power can add up. In larger enterprises, all of the processed emails will require cryptographic checksums, which lesser servers would have trouble dealing with.
Performance degradation would be apparent as the number of real-time messages grows exponentially. Fortunately, the Sentrion DS appliance is very scalable and can handle signing duties for large numbers of emails without any trouble at all. Most organisations will find the scalability to be more than adequate. Even though DKIM is an officially adopted IETF standard, the number of choices and standards available with regards to sender authentication is still limited. More and more ISPs are using DKIM to validate email messages, however, and enterprises that consider ensuring the integrity of email messages to be a priority will find Sentrion very attractive.
Sendmail offers three levels of support: silver (four-hour response time, 20 per cent of hardware cost), gold (one-hour response time, 25 per cent of hardware cost) and platinum (immediate response, 30 per cent of hardware cost). The support site is structured nicely around the various tiers and tells customers how to get help.
Pricing for the appliance starts at £8,250. Because the appliance merely functions as a digital signer, only those organisations that prioritise message integrity and wish to add on to their infrastructure will truly benefit from the product.