As hackers keep on changing the way they attack us, email security has to keep up with all the different ways they can try to get into our systems. But how does email security works?
The basic idea behind email security is to use a combination of technical controls and user awareness initiatives.
The technical side of things is all about using different tools and technologies to filter out emails, scan for any nasty bits, and block anything that looks suspicious.
The human side of email security is all about teaching users about potential threats and the best ways to spot and avoid phishing scams, social engineering attacks, and other email-borne risks.
So, let’s look at these fundamentals in a bit more detail below.
What is Email Security: Key Risks to Know
Email security is all about keeping your inbox safe from phishing, malware, and data breaches. It can be tackled using tools like encryption, authentication protocols, spam filters, and good security habits.
Since emails are constantly being sent and received, they’re vulnerable to attacks. One major issue is misconfigured email servers, like open relay servers, which let hackers send out malicious emails. This is a serious problem in Australia, where many businesses rely on email to share their sensitive information.
Another risk comes from outdated email protocols. For example, Simple Mail Transfer Protocol (SMTP) sends emails in plain text, meaning cybercriminals can intercept and read them. Even though Transport Layer Security (TLS) helps encrypt emails, the Australian Signals Directorate (ASD) warns that it can still be weakened by downgrade attacks.
To verify if an email is legit, businesses can use Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM). These tools help, but they can’t always stop phishing, especially if the email system isn’t well-protected.
But what is the biggest threat? Stolen login details. Hackers use them to break into accounts and send fake emails. According to the 2024 Data Breach Investigations Report, the median loss from a Business Email Compromise (BEC) attack was $50,000—a huge risk for companies.
The market’s got a few options for you to look at. Have a read “The Most Secure Email Provider in Australia.”
Types of Email-Based Attacks
There are loads of different types of email-based attacks out there, and they’re always changing.
1. Phishing Attacks
Phishing is one of the most prevalent email security threats. These attacks use spoofed email addresses and social engineering techniques to trick recipients into exposing sensitive information or downloading malware. Implementing protocols like DMARC can help prevent email spoofing and phishing attempts—learn more about DMARC and email security here.
2. Business Email Compromise (BEC)
BEC attacks involve fraudsters impersonating trusted individuals or organizations to manipulate victims into making fraudulent financial transactions. The FBI’s 2022 Internet Crime Report, which you can read about in “A CISO’s Guide to Email Security,” shows that BEC attacks cost businesses over $2.7 billion in 2022 alone.
3. AI-Driven Social Engineering
With the rise of generative AI, cybercriminals now create highly convincing phishing emails that closely mimic legitimate communication. It makes it even harder to distinguish between genuine and fraudulent messages.
Components of Email Security
To tackle these weaknesses, companies need to put in place a solid email security system with a few key parts.
1. Email Content Filtering
This is the first line of defense you have to do. Content filtering systems would scan email attachments and text for malicious code. It’s preventing harmful emails from reaching users’ inboxes.
2. Authentication Protocols
Email authentication mechanisms such as SPF, DKIM, and Domain-based Message Authentication, Reporting, and Conformance (DMARC) verify email senders’ identities. When properly configured, these protocols reduce the likelihood of email spoofing and phishing attacks.
3. Email Encryption
Encryption protects email content from being accessed by unauthorized users. Transport Layer Security (TLS) encrypts emails in transit, while advanced encryption methods like S/MIME and OpenPGP offer end-to-end encryption.
4. Secure Email Gateways (SEGs)
SEGs monitor inbound and outbound emails, blocking threats like spam, malware, and phishing attempts before they reach recipients.
5. User Awareness and Training
Human error is often the weakest link in email security. Organizations must educate employees on identifying phishing emails, avoiding suspicious links, and using multi-factor authentication (MFA) for added security. Having scheduled training for employees will greatly help to increase awareness of cyber threats
What are the Three Types of Email Security?
Email security has to have lots of different defences to protect against the growing number of threats targeting email communications. One of the approaches is as Esra Altulaihan and colleagues point out, email attacks like phishing and spoofing still pose a big risk.
To tackle any threats, email security can be split into three main Types: Encryption, authentication, and email filtering.
Encryption
Encryption is a way of scrambling the content of an email so that it can only be read by the person you want to see it.
For example, Transport Layer Security (TLS) is a protocol that’s used a lot in email systems. It encrypts emails during transmission, so that unauthorised parties can’t eavesdrop on sensitive information.
Think of TLS as a kind of secure tunnel that keeps your emails safe as they travel across the internet.
The ASD email guideline also suggests using S/MIME and OpenPGP for end-to-end encryption. This means that even if someone intercepts an email, they won’t be able to read it.
For more details, please refer to “How Email Encryption Works: Methods, Protocols, and Can It Be Hacked?
Authentication
The point of authentication is to make sure your emails are coming from the right place. This helps stop people spoofing emails, which is when attackers pretend to be someone they’re not to trick the person reading it.
It’s like checking someone’s ID before letting them into your house.
The ASD email manual recommends using mechanisms like SPF, DKIM, and DMARC as digital signatures for emails. This way, the mechanism lets recipients check who sent the email and that it hasn’t been altered.
In particular, DMARC lets domain owners decide how receiving servers should handle emails that don’t pass authentication checks, which gives them another level of control.
Email Filtering
Email filtering is like a gatekeeper, blocking nasty stuff like spam, phishing attempts and malware-laden attachments before they reach the user’s inbox.
It’s like having a security guard at the entrance of your building, checking visitors before they come in.
The best email filtering solutions use a mix of techniques, including signature-based detection, heuristic analysis, and machine learning algorithms, to spot and quarantine suspicious emails.
“A CISO’s Guide to Email Security” shows how crucial email filtering is in the fight against the growing number of complex phishing attacks, which often use social engineering and fake email addresses to trick users.
How Does Email Security Works?
Email security process is a multi-layered defense system that integrates technical controls, user awareness, and administrative policies. The process involves:
- Filtering Incoming Emails: Spam filters and antivirus software scan for malicious content.
- Blocking Suspicious Activity: Sandboxing isolates attachments to detect harmful behavior.
- Verifying Senders: SPF, DKIM, and DMARC confirm email legitimacy.
- Educating Users: Training programs teach employees how to recognize email threats.
- Implementing Strong Password Policies: Multi-factor authentication adds an extra layer of protection against unauthorized access.
To stay ahead of evolving cyber threats, businesses should conduct regular security audits and leverage AI-based monitoring tools as part of their email security process.
Top Secure Email Provider in 2025
If you’re after a safer way to handle your emails, here are some of the most secure email providers available:
1. ProtonMail
ProtonMail is known for its end-to-end encryption and is based in Switzerland, where strict privacy laws help keep users’ data safe. Key features include:
- Self-destructing emails for extra security.
- AES-256 encryption to protect your data.
- Multi-Factor Authentication (MFA) for an added layer of protection.
2. Tutanota
Tutanota is an open-source email provider, meaning its security measures are fully transparent. It’s based in Germany and follows strict privacy regulations. Key features include:
- Automatic encryption that protects emails from phishing attacks.
- Ad-free experience, even on the free plan.
- Comes with 1GB of free storage, with paid plans offering more features like custom domains.
3. Fastmail
Fastmail is an Aussie-based email provider with servers in Australia, meaning it follows local privacy laws like the Privacy Act 1988. While it doesn’t offer full end-to-end encryption, it does provide:
- Strong encryption for data in transit and at rest.
- Business-friendly features, including shared calendars and email aliases.
- fast and user-friendly experience for professionals.
4. Hushmail
Hushmail is a Canadian email provider that offers PGP encryption and HIPAA compliance, making it a great choice for healthcare professionals and privacy-conscious users. Its key features include:
- Automatic email encryption—no need for extra software.
- Simple, easy-to-use interface
- Ideal for businesses and professionals who need a secure email service.
5. Mailfence
Mailfence is based in Belgium, outside the Five Eyes intelligence alliance, making it a solid choice for privacy-focused users. It offers:
- End-to-end encryption and digital signatures for secure communication.
- Encrypted storage for documents and calendars
- Interoperability with other encrypted email services.
Each provider offers different levels of security, so the best choice depends on whether you prioritise privacy, transparency, or business-friendly features.
How Does Interscale Support Your Email Security?
Given the complexity of email security, businesses require reliable solutions to safeguard their communications. Interscale offers advanced email security features, including:
- Phishing Detection: Identifies and blocks phishing attempts.
- URL and Attachment Analysis: Scans links and attachments for malicious elements.
- Policy-Enforced Encryption: Ensures sensitive emails remain secure.
- Cloud-Based Security: Provides seamless protection without impacting network performance.
By leveraging our email security solutions, businesses can prevent email threats before they reach their networks, reducing administrative overhead and enhancing security. Feel free to look at our Interscale IT Email Security & Protection Service page.
Let’s discuss your email issues and how we can help you tackle them.
In Closing
No matter what approach you take, it’s important to keep in mind the ever-changing nature of the threat landscape. That’s why we at Interscale are always on standby, 24/7, to keep you in the loop about the latest email security measures and best practices.
So, how does email security works to keep your sensitive information safe? It’s about keeping up with the latest cyber attacks and staying one step ahead.
