Although email providers have significantly strengthened their security filters in recent years, spam and fraudulent emails remain one of the main gateways for digital scams, credential theft, and malware distribution. From unwanted advertising messages to phishing campaigns designed to impersonate legitimate brands or services, email continues to be one of cybercriminals’ favorite channels to reach potential victims via email.
In this situation, ESET, a leading cybersecurity company, analyzes the main reasons why an email inbox can suddenly fill up with spam or suspicious messages, as well as the measures that help minimize risks and avoid falling into increasingly sophisticated scams in the use of email.
“A sudden increase in spam may indicate that an email address has been exposed following a data breach or published on clandestine markets related to cybercrime,” explains Josep Albors, director of Research and Awareness at ESET Spain. “Criminals leverage this data to launch more credible and targeted phishing campaigns, using leaked personal information to build trust in the victim via email.”
The 10 reasons why your inbox is filled with spam and scams
According to ESET, these are some of the most common factors that explain the increase in spam and malicious messages in email:
- Leaks and data leaks: Email addresses stolen in security breaches are often sold on underground forums to launch massive phishing campaigns.
- Use of increasingly sophisticated phishing kits: criminals have ready-made tools to create convincing campaigns capable of bypassing email security filters.
- Targeted campaigns: Some attacks use previously leaked information to personalize email messages and make them more credible.
- Current events or specific seasons: Campaigns such as sales, holidays, tax campaigns or major sporting events are often used as a hook to increase the effectiveness of email fraud.
- Use of artificial intelligence: AI makes it possible to generate email messages that are more realistic, personalized and difficult for users to detect.
- Automated tracking of public addresses: Bots and automated tools collect email addresses published on social networks, forums or websites.
- Previous interaction with suspicious messages: replying, downloading files, or clicking on email links confirms to attackers that the account is active.
- Spam bombardments to hide real alerts: Some campaigns deliberately clutter the email inbox to hide important notifications, such as bank transactions or fraudulent purchases.
- Registration for promotions or unreliable services: using the primary email in sweepstakes, promotions, or unknown platforms increases exposure to commercial and fraudulent campaigns.
- Acceptance of commercial communications without reviewing permissions: many platforms share or reuse email contact data for advertising purposes, increasing the volume of spam received.
Criminals leverage this data to launch more credible and targeted phishing campaigns.
How to reduce spam and avoid falling into fraud
Given the increase in these threats, ESET recommends taking a series of preventive measures to protect email accounts and reduce exposure to malicious email campaigns:
- Keep your social media accounts private to prevent automated bots from collecting your email address.
- Don’t click on or respond to suspicious emails, even if they appear to come from legitimate companies that use email.
- Use email cloaking services when signing up for new platforms or online services.
- Check if your email address has been compromised using specialized data breach monitoring tools.
- Keep your security software up to date, especially solutions with anti-spam and anti-phishing protection for email.
- Avoid using your primary email for irrelevant registrations, promotions, or public Wi-Fi connections.
“As with much of cybersecurity, email continues to be a constantly evolving terrain between attackers and defenders. Having good practices and appropriate security solutions remains the best way to keep your email inbox protected from waves of spam and fraudulent campaigns,” concludes Albors.
