In 2025, you might think that the most successful cybercriminals have extensive technological knowledge. But contrary to popular belief, the most effective hacking techniques require little-to-no technical skill at all. Because AI has made phishing attacks more sophisticated, malicious emails are still the single biggest threat to your business’s online security in 2025.
According to Microsoft’s Digital Defense Report(new window), an AI-automated email is 4.5 times more likely to result in someone clicking a malicious link, yielding a 54% clickthrough rate (as opposed to a 12% clickthrough rate without the use of AI).
As deepfake impersonations and hyper-targeted, AI-enhanced phishing campaigns increase, it’s imperative that owners and managers not only enforce email security best practices but actively foster a security-minded culture within their organizations.
Why you need to update your email cyber security in 2025
In 2025, attackers rely on deception, impersonation, and human error instead of code to get ahold of you or your company’s data. Because of this, a hacker only needs an internet connection and an email account to employ a devastating email scam. Phishing email attacks remain the most common and devastating attack method(new window), or vector. And according to a Cyber Security Foundation report, 72 percent of businesses received at least one phishing attack in 2024.
In 2025, these attacks use various AI and social engineering strategies that target vulnerable employees rather than infrastructure. AI-generated phishing emails can mimic tone, language, and even voices or faces, making them harder to detect and more likely to succeed. Today’s phishing tactics and identity scams appear so real to the human eye, but that simple email can wreak havoc on your company’s finances.
Worried about email cyber security? In this article, we explain how you can protect your business and minimize your organization’s vulnerability by implementing the best email security practices for 2025.
Protect your business with these email security best practices
Since hackers tend to exploit human vulnerabilities more than technical ones, your company’s email cyber security strategy should focus heavily on your employee’s behavioral awareness, ensuring they have an active role in your company’s protocols.
Consider adopting a zero-trust framework, in which everyone in your organization adheres to strict verification and authorization principles. In addition to a zero-trust environment, we’ve outlined 10 email security best practices for employees that you can start implementing right away.
1. Educate your employees
Security begins with awareness. The most important thing you can do is make security a priority among your team. Start by understanding common phishing attacks and share email security tips with your employees regularly.
If you receive an attack, share the email with your team to keep them alert, and encourage staff to report suspicious messages, even when they’re unsure. Make sure to educate your team on traditional phishing techniques and modern threats, including:
- Lots of spelling mistakes — or — oddly professional emails with no typos or grammatical errors (likely AI-generated)
- Spoofed email domains that closely resemble legitimate ones (like user@pr0ton.me)
- Fake video or audio messages impersonating company executives
2. Limit public information
Attackers can’t know what they can’t see, and they can’t target your employees if they don’t have their contact information. Avoid publishing personal email addresses, phone numbers, and employee titles on your company website or in any online directories, as all of these informational cues can help cybercriminals engineer an attack and compromise your email cyber security.
Additionally, use email aliases whenever possible. Proton’s hide-my-email aliases are unique, randomly generated email addresses you can share publicly instead of your real email address, meaning you can create accounts, receive emails, and reply in your Proton Mail mailbox without revealing your identity.
With a Proton Mail Business plan, you can create unlimited hide-my-email aliases to shield your personal inbox and reduce your phishing risk.
3. Verify unusual requests
Deepfake audio and video scams are on the rise. You might recognize an email or text message that appears to come from the CEO asking for an urgent wire transfer as fake, but that message can appear far more convincing when backed by seemingly real audio or video.
Never rely on only one mode of communication for sensitive actions. Instead, always verify unusual requests, like bank transfers, using a second communication channel. If you receive a Slack or email message asking for money or login credentials, call the person directly to verify their request.
4. Double check email addresses and domains
Phishing attacks are rarely perfect. Oftentimes there’s a tell, such as a bizarre address (e.g. service145@mail.145.com), an unusual link (e.g. amazon.net.ru), a high number of typos, or, in the case of AI, a rigid and almost too-professional sounding email that just doesn’t sit right.
Proton Mail flags suspicious domains, but employees should be trained to double-check everything, especially when money or credentials are involved. When receiving email, look closely at the full email address and domain. If it looks suspicious, report it.
5. Be wary of spoofed links, attachments, and QR codes
In 2025, attackers increasingly use QR codes (called quishing) in phishing emails to avoid detection by spam filters. These codes can lead to credential-harvesting sites or trigger malware downloads. Additionally, attachments can contain malware, such as ransomware or spyware, that can compromise the device or network. Proton Mail auto-scans links and attachments using real-time threat intelligence for your safety — but there are a few practices you should always employ when opening emails, including:
- Do not scan QR codes from untrusted sources.
- Always hover over links to inspect the destination (you can retrieve the original URL using this tool(new window)).
- Don’t open attachments unless you’re certain of their origin and intent.
6. Never enter information from an email link
Even the most convincing login pages can be fake. If an email directs you to log in to your account and you haven’t requested to reset your password, then the password reset link is likely part of a phishing attack.
When in doubt, ask. Your employees should be instructed to check with IT staff or a manager any time they have doubts about an email.
Employers should also encourage employees to bookmark the company’s official login portal and avoid clicking on login links in emails altogether.
You can also use Proton’s password manager to autofill your credentials. Password managers, in addition to helping you use strong, unique passwords, can detect fake websites for you and won’t input data into spoofed sites. If the password manager doesn’t recognize the login page, it’s likely a phishing attempt.
7. Enable and enforce two-factor authentication (2FA)
Make 2FA non-negotiable. Proton allows you to enable two-factor authentication and make it mandatory for your organization. In addition to requiring a standard username and password, 2FA requires employees to enter a six-digit code generated by their phone. With 2FA, if a hacker learns an employee’s password, they would still be prevented from logging in.
8. Monitor account activity
With Proton Mail’s enhanced Authentication Logs, you can view recent logins, device information, and location data to detect unauthorized access. If a user logs in from an unexpected country or device, Proton will flag the activity and allow you to remotely terminate sessions.
9. Use a secure, encrypted VPN
Proton VPN for Business encrypts the online traffic of your business to provide an extra layer of defense against hacking and surveillance. When you connect to Proton VPN’s unique Secure Core architecture, your internet traffic is routed to a VPN server in a privacy-friendly country, such as Switzerland, Iceland, and Sweden. That means any third-party monitoring your traffic will only be able to trace it back to the edge of Proton’s VPN network, allowing you to conduct business with a strong sense of security and privacy.
Proton VPN for Business routes traffic through privacy-respecting countries, hides user IP addresses, and defends against deep packet inspection(new window), location tracking, and other network-based attacks.
10. Adopt a secure email provider with built-in threat protection
While proper email security training is essential, your provider should do the heavy lifting. It’s important to choose an email service provider that takes your company’s security seriously.
Proton Mail uses advanced end-to-end encryption to make sure nobody, not even Proton, can access your data. We’ve also implemented a number of unique security features designed to minimize the threat of email-based attacks on your small business, including several dedicated anti-phishing technologies.
Using Proton Mail is just like using any other email provider, so you won’t need to do any extra training with your team. There’s no special setup required, and no complex onboarding — just secure, encrypted communication, automatically.
Protect your business with Proton
The tools used by attackers have changed, but the core weakness remains the same: human error. In 2025, even a tech-savvy employee can be fooled by a well-crafted impersonation or AI-powered scam. That’s why Proton was built to provide privacy-first tools so you and your team can communicate and conduct business securely and effortlessly.
By using Proton Mail’s suite of tools, you can communicate privately, store and share files securely, manage your team’s login details and bank cards, and ensure your internet connection is always private.
We built our user-friendly platform with familiarity and ease of use in mind. By following the email security best practices above and choosing a security-focused email service, you can significantly reduce your chance of falling victim to an email attack while keeping your business safe.
