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Single hacked domain brings down Internet Service Provider as customers exit in droves | Email Secur

Posted by Geraldine Hunt on Mon, May 26th, 2014

Just one compromised email domain resulting in I.P address blacklisting by Email Service Providers can destroy an ISP's reputation.  It is every ISP's nightmare - a single spammer causes an I.P address -or worse, a block of I.P addresses - to be blacklisted by multiple RBLs and ESPs. Inevitably, innocent bystander domains using the same I.P addresses for outbound email are blocked too. The helpdesk floods with complaints, and the forum is ablaze with vitriol.

Swapping over a new I.P address or netblock temporarily solves the problem, but it will take months to rehabilitate the blacklisted addresses, and the problem will recur. It's just one of the results of the limited number of IPv4 adresses.

It is not simple to implement the architecture to manage the risk - rate limits per sending and recipient domain, IP netblocks that can be switched over in event of blacklisting, setting up alerts and monitoring logs. Add to this the frustrating and time consuming process of getting delisted, and slowly "warming up" new or rehabilitated IP addresses to the level of  accepted by the Email Service Providers. Or at least - that's how it used to be. But for ISPs and MSPs, life just got easier.

SpamTitan V6.3  released this month, with sophisticated spam blocking is simple to implement and also allows easy management of outbound email filtering. 

How SpamTitans outbound email filtering works : 

SpamTitan protects outbound I.P addresses and business reputation by: 

1) Scanning and cleaning all outbound email using the same technology as for inbound email.

2) Rate limiting email by any combination of senders and/or recipients

  • - Domain
  • - I.P address range
  • - Email address

3) Alerting the sytems administrator of rate threshold violations

4) Rotating the sending I.P address through a pool of addresses to both manage and minimize risk to lower the risk of: 

  • Outbound spam
  • Business and email I.P address reputation damage due to blacklisting as a spammer

MSPs  and Service providers with multiple client domains can use SpamTitan to effectively control and protect their valuable I.P addresses, safely maintain email sending service levels, and ensure that their customers spam-free email is delivered without let or hindrance by Email Service Providers for example.

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