Why Email Security Matters
Email is one of the few channels through which a complete stranger can deliver content directly to you, which is why it has been targeted again and again as an entry point for cyberattacks. Many phishing attacks begin with an email, and email is also used to distribute ransomware and malware.
The standards email is built on date back to RFC 733 for the message format in 1977 and RFC 821 for the SMTP transport in 1982, and sender authentication was added later. That is why sender spoofing and message interception remain technically possible, and why users need to understand the risks and take precautions themselves.
How to Spot Phishing Emails
Phishing emails impersonate legitimate services or organizations to steal personal information or login credentials. Watch for these red flags:
Check the Sender's Address
Display names are easily spoofed, so always check the actual email address. Look for addresses that subtly differ from the real domain (e.g., support@amaz0n.com, info@paypa1.com). For advanced verification, you can inspect the raw message headers to trace the email's true origin - our guide on email header forensics explains how.
Beware of Urgent Language
Messages like "Your account will be suspended" or "You must respond within 24 hours or your data will be deleted" are designed to create panic and cloud your judgment - a hallmark of phishing.
Inspect Links Before Clicking
Hover over links in the email (without clicking) to see the actual URL. Check whether it leads to a domain different from the legitimate one.
Be Cautious with Attachments
Don't open unexpected attachments, especially .exe, .zip, or .docm (macro-enabled Word) files. They may contain malware.
Watch for Unnatural Language
Awkward phrasing, grammatical errors, and unusual greetings are signs of a phishing email. However, natural-sounding text is not proof of safety. Where text can be generated mechanically, awkward wording is no longer a reliable clue, so judge a message together with its sender address and link destinations.
How Email Encryption Works
TLS: Encryption in Transit
Encrypting the connection with TLS when sending and receiving messages has become common practice among major email services. However, email is relayed through several servers, and whether each hop is encrypted depends on what the receiving server supports. The risk of interception in transit is lower, but the message body is handled unencrypted on the servers it passes through.
End-to-End Encryption
This approach keeps email content encrypted from sender to recipient at all times. Not even the email server administrator can read the contents.
- PGP/GPG: An open-source encryption standard; requires technical knowledge
- S/MIME: Certificate-based encryption, commonly used in enterprise environments
- Proton Mail: An email service with built-in end-to-end encryption
- Tuta (formerly Tutanota): Another email service offering end-to-end encryption
Email Authentication Technologies
The following email authentication technologies have been developed to prevent sender spoofing:
SPF: Sender Policy Framework
Domain owners register the IP addresses of servers authorized to send email on their behalf in DNS records.
DKIM: DomainKeys Identified Mail
A digital signature is attached to the email, allowing recipients to verify that the content hasn't been tampered with.
DMARC: Domain-based Message Authentication, Reporting and Conformance
Based on SPF and DKIM results, domain owners can specify how to handle emails that fail authentication (reject, quarantine, or allow).
Best Practices for Safe Email Use
- Don't click links in suspicious emails - navigate to the service directly in your browser
- Verify with the sender before opening attachments
- Enable two-factor authentication on your email account
- Use a strong password and don't reuse it across services
- Keep your email client's spam filter enabled
- Disable automatic image loading in HTML emails to block tracking pixels
- Use an end-to-end encrypted email service for sensitive communications
Use IP Check-san to check your connection security and verify that your email traffic is protected by proper encryption. Understanding social engineering tactics will also help you recognize phishing attempts before they succeed.
Related Glossary Terms
Frequently Asked Questions
Are all email attachments dangerous?
Not all of them, but as a rule you should never open attachments from unknown senders. Files such as .exe, .js, .vbs, and macro-enabled Office documents are especially high risk. Even from trusted senders, verify unexpected attachments before opening.
What happens if I reply to spam?
Replying confirms to the sender that your address is active, which brings even more spam. Your reply can also expose personal information. The best response is to delete spam without opening it.