One common email threat involves the delivery of malware through spam messages. Attackers often send emails containing malicious attachments that can infect a system when opened. These messages may look like they come from trusted sources such as colleagues or reputable companies, making them more convincing. Once executed, the malware can steal sensitive data, propagate additional spam, or even compromise system control.

Phishing attacks occur when cybercriminals send deceptive emails that appear to come from legitimate organizations like banks or service providers. These emails typically prompt recipients to share sensitive details such as login credentials, account numbers, or personal identifiers. The stolen information is then misused for fraud, identity theft, or unauthorized access.

Email systems can also be disrupted through malicious bot activity and distributed denial-of-service (DDoS) attacks, sometimes referred to as mail bombing. In such cases, attackers flood email servers with excessive traffic from multiple sources, causing system overload. This can lead to service interruptions, delayed email delivery, or even storage exhaustion on mail servers.

Email relaying is a technique where attackers exploit an unsecured mail server to send unauthorized emails on their behalf. This method is commonly used for spam or phishing campaigns. Since the emails originate from a trusted server, they are harder to detect and can damage the server’s reputation, potentially leading to IP or domain blacklisting.

Email spoofing involves forging the sender’s email address to make messages appear as if they are coming from a trusted source. The objective is to deceive recipients into performing harmful actions such as clicking malicious links or sharing confidential information. Spoofing can occur in various forms, including domain spoofing and man-in-the-middle spoofing techniques.

Impersonation attacks happen when an attacker pretends to be a legitimate person or authority to gain access to sensitive information or disrupt operations. These attacks are often convincing because attackers may use stolen credentials or personal data. Warning signs include unusual requests for confidential information or subtle changes in writing style that do not match the real sender.