Protect Against Outbound Spam

spam-filteringMost of what an email administrator deals with on a daily basis is protecting the inbox of his or her user base. With the number of spam and phishing attacks on the rise, there is little time for anything else.

While management is beginning to see the threat that illicit emails pose to their organizations, an increase in the dollars available to keep the inbox spam free might not be enough to completely protect your organization from the problems associated with spam. Sure, users won’t complain as much and you will reduce the threat landscape from incoming email attacks; but if you are not allocating enough resources to dealing with outbound email threats then your organization could be finding itself dealing with some unforeseen problems.

What is an Outbound Email Threat?

Outbound email threats are simply spam or phishing attacks that originate from your mail servers. At one time, mail servers themselves were often left unprotected or they were configured to be open relay servers so the problem was with the server itself. However mail server security has been addressed and most network appliances will help to protect this layer. Nowadays, illicit emails generally come from two sources: your marketing department or your endpoints.

Email Marketing Spam

When I was serving as a consultant to a non-profit organization the marketing director decided to send an email to as many education professionals as she could in a particular state. Obtaining a list was easy and she went ahead and crafted up a nicely written email to promote the company’s services, which were free and actually quite beneficial to teachers and students. Despite my warnings about sending unsolicited mail, the CEO was determined to launch the campaign believing that no one would find fault with a non-profit that was trying to give something away to schools.

I’m sure most people know how this story ends, the address was blacklisted by the various block lists because so many people reported the message as spam and because it was all sent from one address at one time. Care was not taken to obtain a legitimate mailing list nor was the bulk mailing done responsibly. Being overridden by the CEO, there was not much I could do but clean up the mess and quietly think, “I told you so,” to myself.

Spam From Your Endpoints

Spammers are smarter than most marketing professionals who send out email blasts. They know that a mass mailing originating from one address at one time will certainly raise a few eyebrows. Instead, they send out steady streams of malicious emails from large botnets of compromised computers.

Small to medium sized companies can find themselves targeted by spammers looking to increase the size of their botnet. Using malware, they can take over any number of vulnerable computers in your network and use them to send spam.

The problem for you is that when ISPs start seeing spam originating from your mail servers you could easily find yourself on one or more of the DNS block lists.

Dealing With Outbound Spam

Being labeled as a spammer can do some heavy damage to your organization. Those who have found themselves in this situation often:

  • Suffer damage to their reputation
  • Find themselves having to defend themselves against legal action
  • Spend time and money clearing their name with the block lists

Proactively dealing with outbound spam is a much more cost effective, and responsible, way to deal with this problem.

Start by working with upper-level management to educate anyone who would be sending newsletters, marketing materials or any other type of mass emails. Create policies that govern how and when these emails can be sent. When a department or individual is planning to use a mass email campaign be sure that everything is reviewed beforehand.

To protect against spam originating from your endpoints, the solution is much more simple. Utilize the right technologies to guard against outbound spam. If you are using Microsoft Exchange, make sure that in the Outbound spam preferences menu (under Protection > Outbound spam) is configured to alert you when suspicious email is being sent. In addition to this, make sure that your anti-spam solution offers outbound email protection as well.

All too often, outbound email is forgotten in the fight against spam. You will be doing your organization a tremendous favor by addressing it before it is too late.

Written by Jeff


  1. L.J. · August 22, 2013

    Stubborn managers are actually the biggest risk for outbound spam. I’ve had similar experiences, especially with those marketing types who think everybody is open to receiving new messages with new opportunities and it is not possible to convince them many people hate these messages, even if the opportunities are legit. The worst is when the address gets blacklisted, this is your fault because you are in charge of IT and this is an IT issue. Nice, uh?

  2. Edwin · August 23, 2013

    Outbound spam is one of the most common problems by marketers today. I think it’s because there’s a slight disconnect among the definitions of spam. For example, for a lot of people, spam is an e-mail for Viagra and other kinds of dubious medications. In truth, though, it’s anything unsolicited. What companies should do therefore is to create an opt-in page first before they start sending e-mails.

  3. Yana · March 3, 2014

    @Edwin: I totally agree with you!!! Marketers have very different understandings about spam. Many somehow “categorize” spam. A lot of people believe that spam come mostly in the form of viagra and pharmacy emails. I think this is because it’s the most common type that they see. Some marketers may not even know what phishing is. I believe that marketers can be protected from outbound spam if they are warned that anything unsolicited, unusual, and suspicious can be spam. It will also help if they are given a crash course on email security. And, yes, an opt-in page should be obligatory material for any online marketer.

  4. Arnold · October 1, 2014

    Wow, who would have thought? This article is written in 2012 and still the problem still exists, but in a complete different way. Companies and marketers are spamming their way to us using social media. They’ve never been this noisy. They feel that just because we are in the same platform, we are already open to communicating with them. No, I would like to have a choice whether to interact with them or not. They can tell me more about themselves until I can see value, but I still want to have that sense of control.

  5. Sheena · October 3, 2014

    I am running my own online marketing company here in Dallas, and it’s part our strategy to be a bit more aggressive in how we maximize our mailing list and social media for promotions. But I’m also well aware of the penchant of businesses such as mine to commit “outbound spam.” Thus, I do have some guidelines that I teach my employees when it comes to outbound spam. One, limit the number of e-mails sent in a week. Creating a digest is an excellent example. For updates, use social media as people expect you to do that there. Then newsletters are limited to only once a month.

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