Tag: Dns

Test your mail server security infrastructure with Email Security Grader

Email Security Grader is a free online tool which helps IT and mail administrators evaluate the security of their mail infrastructure. The web site regroups several important tests (spam blacklist, open relay, mx records, smtp/pop3/imap authentication), educates users and makes recommendations for each aspect of email security. (Nov 01, 2010)

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How do you fix a bad reputation?

In an earlier post, I had written about the various security measures to take to prevent losing your good reputation.But what happens if you find yourself on someone’s blacklist? What do you do? (Jan 06, 2010)

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Reverse DNS checking: Is it safe to use?

Every time I do a setup with a customer, the question always comes up: Should we use Reverse DNS checking or not when configuring connection-level blocking security measures? (Dec 04, 2009)

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Country-Based Blocking

Is it good or bad? Well the answer is "it depends." If your organization only operates within North-America, for instance, blocking the more prolific spam sources by country may be a very good way to reduce the amount of traffic hitting your MTA. (Oct 30, 2009)

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SPF woes with third party services … a workaround.

Many people use SPF (Sender Policy Framework) as an anti-spoofing measure. They create an SPF record in their DNS zone for their domain. From time to time though, some customers will do business or use third party services that will send out Email on their domain's behalf and unfortunately, this will cause recipient MTAs to hard-fail or soft-fail these messages. (Sep 04, 2009)

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