How to Send Secure Email in Gmail: All Ways in 2025

Security

Tips

9 min read

Email Security in 2025 and the Need for a Private Email Channel

It’s 2025, and your inbox is more exposed than you think. If you use Gmail, you're likely aware, perhaps uncomfortably so, of the significant risks it can pose to users. These aren't just abstract threats; they range from increasingly sophisticated phishing attacks meticulously crafted by bad actors targeting the massive Gmail user base, to concerns stemming from Gmail's policy itself.

Think about Gmail AI privacy risks – the platform's powerful artificial intelligence systems process your communications to deliver features, but this inherently involves access to your data, contributing to extensive digital fingerprinting.

For some, the mantra is "I have nothing to hide." But pause and consider: your emails, even the most innocuous-seeming ones, can tell a far more detailed story than you might imagine. Patterns emerge, connections are mapped, and profiles are built, sometimes with unsettling accuracy.

And what happens when the stakes are undeniably high? What if you need to send a private document via email? What if you're emailing financial records, legal papers, or even a simple message that’s nobody’s business but yours? This is where the concept of how to send secure email in Gmail becomes critically important.

In this article, we’ll walk you through how to send a secure email in Gmail using every method currently available – including Gmail’s native options and external tools. We’ll also show you why these methods often fall short, and what you can do if you need real privacy, not just the illusion of it.

Is Gmail Secure by Default?

Let’s start with a hard truth: Gmail is not end-to-end encrypted by default. Yes, it uses TLS (Transport Layer Security) to encrypt messages in transit – that is, between mail servers. But once your email reaches Google’s servers, it’s decrypted. Google can technically access the content. So can third-party apps connected to your inbox.

How to send secure email in Gmail becomes complicated when you realize that TLS only protects your data on the way, not at rest. Once it’s on Google’s side, it’s in plain view. Even if they claim not to read your emails anymore (after years of doing so for ad targeting), the infrastructure still exists.

This lack of zero-access encryption is why many – from journalists and startup founders to privacy conscious users – are now actively searching how to send a secure email in Gmail and whether they should switch to Gmail alternatives.

Method 1: Gmail Confidential Mode

What Is Gmail Confidential Mode?

Introduced as a pseudo-security feature, Gmail Confidential Mode lets you send messages with an expiration date. Also confidential mode messages don't have options to forward, copy, print, or download messages or attachments. You can even require an SMS passcode to open the message. Sounds great? Let’s break it down.

Gmail Confidential Mode does not offer end-to-end encryption. In fact, your message is still stored on Google’s servers and can be accessed internally. The recipient receives a link to view the content, not the email itself. Think of it more like a temporary permission slip rather than a locked box.

So if you're wondering how to send secure email in Gmail and believe Confidential Mode makes it bulletproof – it doesn't. But it’s still a useful layer for casual messages.

Step-by-Step: Sending a Confidential Email in Gmail

1. Open Gmail and click Compose.

2. In the bottom toolbar, click the lock icon with a clock – that’s Confidential Mode.

3. Set expiration (e.g., 1 day, 1 week).

4. Choose whether to require SMS passcode. If you choose "SMS passcode," make sure you enter the recipient's phone number, not your own.

5. Write your email and click Send.

⚠️ A Note for Google Workspace Users: If you're using Gmail as part of a Google Workspace account, your ability to use Confidential Mode hinges on your administrator's settings. The administrator must first enable Confidential Mode for the organization. Conversely, they also wield the power to disable it entirely, meaning users within that organization would not be able to send messages in Confidential Mode, regardless of their individual desire for this type of feature. For the details on these admin controls, check Google's official guide for Workspace administrators.

Step-by-Step: Opening a Confidential Email (Recipient Experience)

If they’re using Gmail: it opens like a regular email (until the expiration date or until the sender removes access).
If they’re using another provider: they get a link to view it on a secure web page.

If SMS verification is enabled: they’ll receive a text with a passcode to open the email. This passcode is sent by Google via SMS to the phone number the sender provided.

⚠️ Bear in mind that confidential mode helps to prevent recipients from accidentally sharing messages. However, it cannot prevent them from taking screenshots or photos of your messages or attachments. Recipients can also use malicious software to copy or download messages and attachments.

Pros and Cons

Pros:

Built into Gmail, no plugins needed
Message can self-destruct after a time
The sender can revoke message access at any time
Optional SMS code adds friction for bad actors

Cons:

No end-to-end encryption
Still accessible to Google
Not compatible with email clients outside Gmail
Requires providing recipient's personal information (if SMS enabled)
The need to know recipient's phone number (if SMS enabled)

So, while it helps, Confidential Mode isn’t a real solution for users truly asking how to send a secure email in Gmail – especially when dealing with medical data, legal contracts, or sensitive business IP.

Method 2: S/MIME in Google Workspace

If you’re a business owner wondering how to send secure emails in Gmail using enterprise-grade encryption, you could consider S/MIME (Secure/Multipurpose Internet Mail Extensions). However, it’s not straightforward to set up, and it only works within the Google Workspace ecosystem (formerly G Suite).

What Is S/MIME and How Does It Work?

S/MIME enables emails to be encrypted and digitally signed using certificates. This ensures that the content of the message cannot be read or altered in transit. For this to work, both the sender and the recipient must have S/MIME certificates that are installed and trusted.

So, while it provides enterprise users with a secure email communication option, it’s highly conditional. If the recipient doesn’t support S/MIME, it's essentially useless.

For Google Workspace Administrators: Enabling and Managing S/MIME

If you're an admin, here's what you'll need to do:

Log into the Google Admin console.
Go to Menu > Apps > Google Workspace > Gmail > User Settings.
On the left, under Organizations, select the domain or organizational unit (OU) you want to configure. To use advanced S/MIME controls for root certificates, enable S/MIME at the top-level organization.
Scroll to the S/MIME setting and check the box Enable S/MIME encryption for sending and receiving emails.
(Optional) Check the Allow users to upload their own certificates box if you want to permit users to manage their own S/MIME certificates within their Gmail settings.
Configure any additional controls, such as uploading root certificates or allowing SHA-1 (not recommended unless strictly necessary).
Click Save. It may take up to 24 hours for the changes to take effect, although this often happens more quickly.
Once enabled, instruct users to reload Gmail to apply the changes.

This means actively managing cryptographic keys – a complex task not suitable for casual users. It’s a full-on IT operation.

Certificate Management by Administrators

Admins are responsible for issuing, renewing, and revoking certificates. These must be obtained from a trusted Certificate Authority (CA). If even one certificate is compromised or misconfigured, the whole email security chain breaks.

Also, admins could allow users to upload their own certificates: this offers flexibility but can be a support nightmare and introduce inconsistencies.

For Google Workspace Users: Sending S/MIME Encrypted Emails

Once S/MIME is enabled by the Google Workspace administrator, users will see a lock icon when composing an email.

In Gmail, click Compose to start a new message.
Enter the recipient's email address in the "To" field.
To the right of the recipient's email address (once entered), click this lock icon.
(Optional) A small pop-up or dialog may appear. Click View details to change S/MIME settings for this specific email, such as choosing to encrypt and/or sign the message, or to adjust the level of encryption if multiple options are configured by the admin.
Compose your message and add attachments as usual.
Click Send. If S/MIME is correctly configured for both you and the recipient, and public keys have been successfully exchanged (Gmail's hosted S/MIME often handles this automatically for communications within or with other similarly configured domains), the email will be encrypted and/or signed. Otherwise, the email won’t be encrypted end-to-end.

For Google Workspace Users: Uploading Your Own S/MIME Certificate (If Permitted)

After your Google Workspace administrator has enabled S/MIME and (if applicable) allowed users to upload their own certificates, reload Gmail in your browser.
Navigate via the Settings gear icon > See all settings > Accounts (or Accounts and Import).
Find your email address in the Send mail as: section and click Edit info. If this "Edit info" option or the subsequent certificate upload option is not visible, your administrator has not enabled user certificate uploads. Contact your administrator.
In the window that appears, click Upload a personal certificate, select your S/MIME certificate file (usually a .p12 or .pfx file), click Open, and enter the password that protects your certificate's private key when prompted.
Click Add certificate.

Pros and Cons

Pros:

Real encryption for Gmail within Workspace
Digital signatures confirm sender authenticity

Cons:

Only works within Google Workspace
Requires complex setup and certificate management
Recipient must also support and trust your S/MIME certificate
Cost. While some CAs offer free S/MIME certificates (often with limitations), certificates from well-known, broadly trusted CAs for enterprise use can involve significant costs.

S/MIME is a powerful option – but only for organizations willing to invest in the infrastructure. If you’re an individual user searching how to send a secure email in Gmail, this likely isn’t your solution.

Method 3: Sending Encrypted Attachments via Gmail

When you need to send sensitive files but aren't ready (or able) to dive into the complexities of S/MIME, or when Confidential Mode feels insufficient, you might consider encrypting the files themselves on your device or using third-party tools.

Yes, it’s old school. But it works – when done right.

How to Protect a File and Send It Via Gmail

1. Create Your Document
Write what you need – whether it’s a contract, personal message, credentials, or a medical file. If it’s just text, consider typing it in a Word or Google Doc and exporting as a PDF.

2. Use Desktop Tools:

Windows (ZIP + Password):
- Right-click the file > "Send to" > "Compressed (zipped) folder"
- Use a tool like 7-Zip to add AES-256 encryption: Open 7-Zip > Add to archive > Choose ZIP format > Set a strong password > Choose AES-256 encryption.
macOS (Password-Protected PDF or Folder Encryption):
- Open the PDF in Preview > Go to File > Export > Permissions… > Click ‘Require Password to Open Document’ > Set a strong password.
- Place your file inside a new folder > Open Disk Utility > Go to File > New Image > Image from Folder > Select the folder and choose 128-bit or 256-bit AES encryption > Set a strong password > Save the encrypted .dmg file.

Third-Party Tools (Cross-Platform):

VeraCrypt: Create an encrypted volume and store files inside. Supports Windows, macOS, and Linux.
WinRAR (Windows): Offers AES-256 encryption when creating RAR archives.
Keka (macOS): Encrypt archives with strong passwords.

3. On Mobile Devices:

iPhone: Use apps like iZip or PDF Expert to encrypt and zip files.
Android: Use apps like ZArchiver or Adobe Acrobat to apply password protection.

4. Email the Encrypted File via Gmail
Attach the file as usual – nothing changes in Gmail’s interface.

5. Share the Password Separately
Never send the password in the same email. Use Signal, Telegram’s Secret Chat, a phone call, or any other secure messaging app.

What Will Be Needed From the Recipient?

The correct software to open PDFs or ZIPs (like Adobe or 7-Zip)
The password you provided

Without it, the content stays locked.

Pros and Cons

Pros:

Works on any platform
Easy to implement with free tools
No need to change email provider

Cons:

Relies on password strength and safe delivery
Not truly seamless or foolproof
Recipient must have software and know how to open the file
Google (and potentially others) can still see the email body

Method 4: Third-Party Encryption Add-ons for Gmail

Several third-party tools aim to simplify the use of PGP/GPG with webmail services like Gmail.

The PGP Option: Mailvelope and Others

Mailvelope is one of the most popular browser extensions for secure Gmail. It integrates with your Gmail inbox and allows you to encrypt, decrypt, and sign messages using OpenPGP.

How It Works:

Open your preferred web browser (e.g., Google Chrome, Mozilla Firefox, Microsoft Edge)
Go to the official Mailvelope website or directly to your browser's extension/add-on store (e.g., Chrome Web Store, Firefox Add-ons).
Install the extension
Generate or import your PGP keypair (private + public keys). Read more about it Mailvelope’s documentation
Exchange public keys with the recipient
Compose your message inside Mailvelope’s secure editor
Encrypt and send

⚠️ Note: if you’re using Gmail as a part of a Google Workspace subscription, you will have to purchase a Mailvelope Business for Workspace license.

What Will Be Needed From the Recipient?

Their own PGP-compatible email client or extension
Your public key
Their private key and passphrase

Pros and Cons of Using Encryption Extensions

Pros:

End-to-end encryption
Free, open-source options available
Works across email providers

Cons:

Complex setup for beginners
Key exchange can be a hassle
Requires tech-savvy recipients
Browser extension vulnerabilities
Depends on third-party tools – you must trust they’re secure and updated

If you're asking how to send secure email in Gmail and you're comfortable with a bit of setup, Mailvelope and similar tools give you genuine privacy – but they also introduce friction. Most people don’t want to manage keys or teach their contacts how to decrypt messages. Reliance on third-party extensions requires your trust in these tools. A compromised, outdated, or discontinued extension could undermine your entire effort to achieve a secure email.

That’s exactly why many are now switching to encrypted email services built for simplicity – like Atomic Mail.

When You Need Real Email Privacy with No Headaches: Choose Atomic Mail

Gmail was never designed with true privacy in mind. And if you've come this far searching how to send secure email in Gmail, you’ve already seen the limitations: half-measures, compatibility issues, and confusing setups.

That’s why it’s time to look for a more secure Gmail alternative.

Atomic Mail is a secure email service built from the ground up for privacy – not ads, not tracking, and not metadata harvesting. No more fiddling with third-party extensions, S/MIME certificates, or manual encryption. Just open Atomic Mail, click "Compose," and choose your encryption level. That’s it.

Why Atomic Mail Is Different (and Better):

Zero-Access Encryption: Your emails are encrypted before they leave your device. We can’t read them – and neither can anyone else.
Advanced End-to-End Encryption: No need for complicated setups or key exchanges. Everything happens automatically.
Multiple Encryption Modes: Choose how to protect each message: for external providers (non-Atomic Mail users), you can select password protection or encryption as a file – both handled seamlessly through our interface. For fellow Atomic Mail recipients, you benefit from advanced Atomic Encryption powered by ECIES, ensuring top-tier security.

Encrypted Attachments: Send secure files with a single click – no external software needed.
Built-in Alias Support: Protect your identity with unique email aliases.
Cross-platform: Works smoothly on desktop and mobile.
Private Account Recovery: Zero-knowledge recovery with a secure seed phrase.

With Atomic Mail, you’re not the product. You're the owner of your inbox.