Linux Hardening in Hostile Networks: Server Security from TLS to Tor

6. Email

Email was one of the first services on the Internet, and it’s still relied on by many people not just for communication but also security. These days, a person’s email account is often tied directly to their login credentials. So, if an attacker can compromise someone’s email account, she can use it as a central hub to trigger password resets and take over the person’s other accounts, or she can send believable emails to the person’s contact list with malicious links or attachments to compromise more people. Beyond email account abuse, one of the primary security concerns for an email server administrator is preventing spam. Email servers are often the target of spammers who use insecure or misconfigured email servers on the Internet ...