What Is Email Spoofing?

What Is Email Spoofing
Yurii Bitko Yurii Bitko 12 march 2024, 15:45 314
For beginners

What is email spoofing?

Email spoofing is a cyber threat that involves sending emails with a fake sender address. The aim is to trick recipients into believing the message is from a trusted person and follow their suggested instructions.

In spoofing attacks, the malicious actor uses forged email headers to trick the recipient's mail client into displaying the fake address instead of the attacker’s actual address. Most people won't realize they've received forged emails unless their email system explicitly tags the email as suspicious.

If someone gets tricked by spoofing, they could accidentally download malware or give up sensitive information at the attacker’s suggestion.

The difference between email spoofing and phishing

In a hypothetical phishing attack scenario, a person receives an email that looks like a hacking attempt notification from their bank. By following a link inside the letter to change the password, the person opens a page that is identical to their bank’s password reset page. Upon entering their current password, they give the attacker access to their funds.

Email spoofing and phishing are related terms, and people often mistake them for each other. Phishing involves using the entire email content to trick the recipient, instead of faking just the sender address. While both have the same goal of tricking recipients into following the attacker’s instructions, they function differently.

Spoofing Phishing
Spoofing is an email-based attack vector. Phishing can be used via email or any other communication medium.
Spoofing can be an element of phishing (the attacker can use both simultaneously). Phishing isn’t an element of spoofing, it’s a broader category.
Spoofing involves exploiting the email server’s vulnerability. Phishing focuses on tricking the email recipient, often with social engineering methods.

How email spoofing works

In email spoofing, the malicious actor uses scripts to forge the email header fields the recipient can see in their email client, most notably the “From” field. This type of forgery is possible because the Standard Mail Transfer Protocol (SMTP) by itself doesn’t have a built-in method of authenticating email addresses.

Engineers have developed a number of email authentication and security techniques like SPF, DKIM, reverse DNS check, etc. However, these techniques need to be supported by both the sender’s and the recipient’s mail server. There’s no use in having a properly configured SPF record for your domain, if the receiving party does not check it at all. And even if it does perform all the necessary checks, their system might be configured to just tag a spoofing email as suspicious, instead of rejecting it. And unfortunately, people sometimes might ignore or overlook the system's warnings.

If a spoofing message does make it to the user’s mailbox, the “From” field will display an impersonated address. The recipient may think they’re interacting with a legitimate person and not an impersonator. This way, someone can try to spoof your boss’s email address and ask you to divulge sensitive information, click links tainted by malware, or suggest other harmful actions.

Why is email spoofing dangerous?

Email spoofing is dangerous for many reasons, including:

Identity cloaking

Spoofing allows hackers to hide their real identity. They impersonate trusted friends, relatives, and brands to attempt to trick users into doing their bidding. Spoofing allows malicious actors to hide in plain sight, making emails less secure for global users.Spoofing allows hackers to hide their real identity. They impersonate trusted friends, relatives, and brands to attempt to trick users into doing their bidding. Spoofing allows malicious actors to hide in plain sight, making emails less secure for global users.

Tarnishing the impersonated person’s reputation

Attackers impersonate people or businesses whose reputations can be tarnished by these malicious activities. Assume you receive a message pretending to come from a trusted address with instructions to download a specific app. That app turns out to be malware, which you later discover and delete. You may become hesitant to interact with that trusted address even if you know the owner was impersonated.

Personal and professional damage

Spoof email attacks can do sizable damage to an individual or business. A spoofed email might trick the recipient into giving up sensitive information like social media passwords, corporate passwords, bank account details, etc. With such information, the attacker could steal money or leak information that harms the good standing of the affected person.

Bypassing blocklists

Many email clients allow users to block specific addresses. However, with spoofing spammers may try to bypass such blocklists and continue to message their targets. If successful, it becomes a game of cat and mouse between the attacker and their target.

Protecting yourself from email spoofing

We’ve covered how email spoofing works and what its dangers are. But the good news is that you can protect yourself from this type of attack. Below, we’ll dive into the technical and general precautions for avoiding email spoofing.

Technical measures

SPF, DKIM and DMARC Authentication

Sender Policy Framework (SPF), Domain Keys Identified Email (DKIM), and Domain-based Message Authentication, Reporting & Conformance (DMARC) are the most important email authentication tools. They involve domain name owners adding special records to their domain name system (DNS) providers, allowing outsiders to verify their messages.

Don’t hesitate to implement these techniques to prevent hackers from impersonating your brand. With the new sender policy changes being adopted by major email providers, they are becoming mandatory for anyone sending more than a few thousand emails per day.

Reverse DNS lookup

A regular DNS request is aimed at determining an IP address for a given host name. Reverse DNS lookup does the opposite: you use it to find out which domain owns a particular IP address (the one an email is coming from). If the sending server's IP address is not associated with the sender domain, it means the message is likely spoofed.

Anti-malware tools

You should install anti-malware software on your work PCs and mobile phones to detect and block any piece of malware before it causes trouble. This way, even if a malicious email isn’t stopped at the doorway, the malware it contains won’t affect you.

End-to-end encryption

For most demanding scenarios, you may use end-to-end email encryption. All users within your organization can adopt digital certificates for their emails. A digital key will be used to encode every email originating from you. This key encrypts your email’s contents, and only the intended recipient can read it (you’ll give them the decryption key beforehand). Attackers might be able to spoof your email address, but they can’t spoof your email certificate.

Other measures

Cyber awareness training

If you run a business, ensure you provide adequate cyber security awareness training to your employees. Cyber threats are increasing daily, and anyone ignoring them could easily fall victim to them. It’s imperative as an employer to provide cyber awareness training for your staff, helping them learn about spoofing and the techniques for avoiding it.

You can register employees for popular cyber training platforms like Phished, Infosec IQ, Hoxhunt, etc.

Be suspicious of unfamiliar email addresses

Watch out for any strange and unknown address sending you emails. Think twice before interacting with such an email. Verify its origins before taking action and seek expert guidance if compelled. If possible, ignore every suspicious email entirely.

Never give out sensitive information

Establish clear rules at your organization to never send sensitive information via email. This way, even if an attacker successfully spoofs a trusted third party and tries tricking an employee into divulging information, the employee will follow your rule and ignore the attacker.

Links and attachments are the most common vectors for introducing malware; you might fall victim if you don’t pay attention to them. Avoid clicking any attachments or links if you have even the faintest doubts about their origins.

Most email clients have built-in tools to scan attachments for viruses. If your email client supports this feature, ensure you enable and constantly use it.


Email spoofing is one of the biggest email threats, and knowing how to protect yourself from it is vital. Hackers often attempt to impersonate businesses to trick unsuspecting customers into sending them money or confidential information. We’ve explained how to protect yourself from spoofing as a business and individually. Follow our tips, and you’ll likely avoid being spoofed online.

Above all, choose a secure email client and a reputable email service provider (ESP) with sophisticated features to combat spoofing, phishing, and other cyber threats. UniOne fits this profile– we offer a reliable and affordable ESP you can rely on to deliver messages securely and prevent your brand from getting spoofed.

FAQs about email spoofing

What differentiates spoofing and phishing?

Spoofing is a technical hack, while phishing relies more on social engineering. Spoofing involves tricking email client software, while phishing focuses on tricking the email recipient. Spoofing occurs only with emails, while phishing can be carried out via any online communication medium.

How does spoofing work?

In email spoofing, the attacker uses scripts to forge the "From" header in an email, tricking the email client into displaying an impersonated email address instead of the real one the message comes from. The aim is to mislead an unsuspecting recipient by technically impersonating an individual or brand they trust.

What happens when an attacker spoofs your email?

Someone spoofing your email can impersonate you and trick your friends, family, and colleagues into giving up sensitive information or downloading malware via a tainted link. Spoofing is dangerous because most email users don’t closely examine the headers of their messages, making them vulnerable if their email system is not equipped to prevent the problem.

How can I know if an email is spoofed?

You can identify a spoofed email by looking at its headers. Check if the "From" address matches the display name. Ensure the "Reply-To" header matches the sender’s address. Examine the “Return Path” in the email. Look for any SPF and DKIM check failures. If you observe discrepancies, the email is likely forged.

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