Knowing just an email addres, even without the ability to access the inbox, still opens up several risks and possibilities for misuse:
Spam and unwanted marketing
Spammers add known email addresses to mailing lists to flood them with unsolicited advertising, promotions, or scam emails. While this is usually just a nuisance, these emails can sometimes contain harmful links or malware attachments, posing a security threat.
Phishing attempts
Even without inbox access, scammers can send phishing emails to the address trying to trick the owner into revealing passwords or personal information. These emails can look very convincing and appear to come from trusted institutions.
Social engineering and information gathering
An attacker can use just the email address to find more information about the owner. By searching in public databases, social media, and data breaches, they can collect personal details like full name, location, job, or other accounts linked to the email. This information may be used for identity theft or more targeted scams.
Account enumeration and brute force attacks
Cybercriminals can use the email address to test which online services you use by attempting to create accounts or reset passwords. They may also attempt brute-force attacks on accounts tied to the email, guessing passwords or security answers.
Impersonation and spoofing
Malicious actors can send emails that appear to come from your address (email spoofing) to trick your contacts, spreading malware or requesting money or information. This can damage your reputation and put others at risk.
Conclusion
In summary, even if someone does not have access to your email inbox, knowing your email address still poses risks ranging from spam and phishing to gathering personal information for scams. Protecting your address and being cautious with unknown emails is essential for online safety.