Some common threats to email server security include:
Phishing attacks: Deceptive emails designed to steal sensitive information. Spam: Unsolicited emails that can clog your server and harm your IP reputation. Malware: Malicious software that can be sent via email attachments. Brute force attacks: Attempts to gain access to email accounts by trying multiple password combinations. Man-in-the-middle attacks: Intercepting email communications to steal information.