Safentrix

Spams mails are the most annoyingoccupants of an mailbox. However, there are
several technologies that help us do away with them. Safentrix is a cloud-based
enterprise class anti-spam solution which blocks spam before it hits your mail
server. It saves you from virus and other malware getting into your network.
Though there are couple of vendors who offer such kind of solutions, Safentrix
is free. But, they add a simple text to all your mails as an advertisment. And
that's how they earn money. Also, they have a premium service for corporate
clients with added features compliant with industry standards (HIPAA, GLB) has
Service Level Agreement, warranty, etc. Under the premium service, your mails
won't carry the ad.

We evaluated this solution in a true cloud environment. We first built up a
mail server and put it on the public IP. Then we started configuring Safentrix.
For this, we first created a new account. We activated the account from the link
given in the registered email ID. In the second phase, you need to authenticate
that you are the authorized person for the domain to be added to Safentrix.
Create a sub-domain which will be specified by Safentrix. After that, you need
to change the MX record of your domain with the one specified by Safentrix. Also
you need to provide the mail server IP to Safentrix server, for it to forward
the mails after scanning them.

The configuration is easy and you don't require a specialized skills for it.
It provides you two options; add/remove of Delivery MX and add/remove users.
This solution can be integrated with almost all email servers, such as MS
Exchange, Lotus Notes, Qmail, Postfix and Sendmail. It is compatible with hosted
email service providers as well.

To test our setup, we sent a mail from Gmail to safentrix. The mail was
successfully delivered, and the setup was working fine. Then for checking
anti-spam, we randomly picked a spam from the spam folder of Gmail account.
After whitelisting it, we forwarded the mail to Safentrix. Safentrix
successfully blocked the spam and generated a mail which was automatically sent
to the sender. This mail carried a key and a link for the sender to simply
verify that the mail wasn't a spam.  Once that was done, we sent the same mail
again and it was delivered. So, if a human sends a spam he can easily make sure
that the email reaches the inbox, which is not good. This can be solved by
forwarding that spam to Safentrix server, where it will be analyzed at the
backend and blocked globally.

One drawback is that, you can't block a particular mail that you found is a
spam for you and want to block only for your domain. For this, you need to
configure your client at your local machine. Safentrix also provides the live
support for both free and the paid version. We tried this live support ourself
and found it satisfactory. It solved almost all of our queries instantly.

Bottomline: A free anti-spam solution that provides additional level
of security for your mail server.