When you think about spam you probably think about the tons of messages that fill your junk mail folder and make their way into your inbox. Despite advances in spam filtering technology and botnet takedowns, spam is still a big problem. Its goal may have changed – these days a spam message may be more likely to try and steal your personal info or infect your computer with malware than it is to sell you something – but it’s still being pumped out by the millions each day. However, there is another type of spam you should be worried about as well – outbound spam.
This spam, which your computer sends out rather than receives, can cause you some real headaches. For starters, it can fill your inbox with bounce back messages and even angry replies from people foolish enough to respond to spam. If your account sends out spam with a malicious link or attachment, or the kind that sounds like an urgent message from you, on vacation/a business trip in a foreign country who’s been robbed and is in desperate need of money, you could find yourself with some annoyed or concerned customers and associates. That’s the best case scenario. The worst case? Your IP blacklisted, possible CAN-SPAM complaints lodged against you, and a damaged reputation.
What can you do to protect yourself? Make sure your mail server is secure and that there are no open relays. Disable port 25, and look for an anti-virus/anti-spam solution that offer real-time detection, scans for and blocks zombie computers, and blocks reverse engineering techniques. Of course it goes without saying your employees should be trained on good security practices and their passwords should be changed every three to six months. An anti-spam solution that blocks links and certain attachments known to be used to deliver malware is also a good idea.