NevTan Mail is secure, ad-free business email on your own custom domain, with a built-in calendar, meetings, admin controls, and TLS-encrypted connections. This guide will explain exactly how email encryption works, what it protects you from, and how to implement it for your entire team. By the end, you will understand the difference between encryption in transit and at rest, know when to use S/MIME versus PGP, and see how a provider like NevTan Mail handles the technical heavy lifting for you. You will also learn practical steps to verify your current setup and close the most common security gaps that leave business email exposed.
Email encryption scrambles your messages so only the intended recipient can read them. There are two main types: TLS (which protects messages in transit between servers) and end-to-end encryption like S/MIME or PGP (which protects the content itself). For most businesses, TLS is the baseline standard, but you should consider end-to-end encryption for sensitive data like contracts or financial information. NevTan Mail enforces TLS on all connections and provides guided setup for authentication protocols that support encryption.
What You Need Before Starting
Before you dive into configuring email encryption, you need a few things in place. First, you need a business email domain that you control. Encryption protocols like DKIM and DMARC require you to modify DNS records, so you must have access to your domain registrar or DNS hosting provider. Without this access, you cannot authenticate your domain, and any encryption you configure will be incomplete.
Second, you need to decide on your threat model. Are you protecting against casual interception on public Wi-Fi, or are you safeguarding against sophisticated attackers? This decision determines whether TLS alone is sufficient or if you need end-to-end encryption. For example, a real estate agency sending closing documents should treat those files as high-risk, while a marketing team sharing campaign drafts may find TLS sufficient. Third, you need to ensure your email provider supports the encryption standards you plan to use. Not all providers offer S/MIME or PGP support natively, and some charge extra for basic TLS enforcement.
Finally, you should have a basic understanding of your compliance requirements. Industries like healthcare and finance often have specific mandates for data protection that influence your encryption choices. HIPAA, for instance, requires safeguards for electronic protected health information, while GDPR emphasizes data protection by design and by default. If you operate in a regulated industry, document your encryption decisions and review them annually. You should also inventory which of your team members handle sensitive data, because you may need to enable stronger encryption for specific roles rather than the entire organization β which is far easier to do when email, calendar, and tasks live in one workspace.
Step-by-Step Guide
Step 1: Verify TLS Encryption in Transit
The first step to securing your business email is ensuring that all connections are encrypted with TLS. TLS (Transport Layer Security) is the protocol that encrypts the connection between your email client and the server, and between servers during message delivery. When TLS is active, an eavesdropper on the same network sees only ciphertext, not your message content or login credentials.
You can check if your provider supports TLS by looking at the settings in your email client. In most modern clients, you will see an option for SSL/TLS under the incoming and outgoing server settings. For NevTan Mail, TLS is enforced by default on all connections. This means your messages are encrypted while they travel from your laptop to the mail server and from the NevTan Mail server to the recipient's server, provided that the recipient's server also supports TLS. If the receiving server does not support TLS, the message may be sent in plaintext, which is why you should also check the policies of the domains you frequently contact. For a wider look at how encryption fits alongside other defences, see our guide to email security, phishing protection, and TLS encryption.
π‘ Pro Tip: Use a tool like checktls.com to test the TLS configuration of your mail server. It will show you the exact TLS version and cipher suites supported, helping you identify any weak configurations. You should also verify that TLS 1.2 or higher is in use, because older versions like TLS 1.0 and 1.1 have known vulnerabilities. Run this test quarterly, especially after any server or DNS changes.
Step 2: Set Up SPF, DKIM, and DMARC
While not encryption in the strictest sense, SPF, DKIM, and DMARC are essential for email security and work alongside encryption to prevent spoofing. If you have not configured them yet, start with our walkthrough on why business emails land in spam and how domain authentication fixes it. SPF (Sender Policy Framework) is a DNS record that lists which servers are authorized to send email for your domain. DKIM (DomainKeys Identified Mail) is a digital signature that verifies a message wasn't altered in transit. DMARC (Domain-based Message Authentication, Reporting & Conformance) tells receiving servers what to do with messages that fail SPF or DKIM checks.
NevTan Mail provides guided setup for SPF, DKIM, and DMARC. You simply copy the generated DNS records from your domain settings and paste them into your DNS provider. This process typically takes about 15 minutes and dramatically improves your email security and deliverability. Without these records, your emails are more likely to be flagged as spam, and attackers can more easily impersonate your domain. In fact, domains without DMARC records are a primary vector for phishing attacks, because receiving servers have no policy to enforce when authentication fails.
π‘ Pro Tip: Start with a DMARC policy of p=none to monitor your email traffic without affecting delivery. After two weeks, review the reports and move to p=quarantine, then eventually p=reject once you confirm all legitimate senders pass authentication. This staged rollout prevents accidental blocking of your own messages β and pairs well with the rest of our email deliverability best practices.
Step 3: Understand Encryption at Rest
Encryption at rest protects your stored messages, contacts, and attachments on the mail server. While TLS protects data during transmission, encryption at rest ensures that if a server is compromised or a hard drive is stolen, the data remains unreadable. Most reputable email providers, including NevTan Mail, encrypt data at rest using AES-256, the same standard used by governments and financial institutions.
You should ask your provider whether encryption at rest is enabled by default and whether you hold the encryption keys. In a standard setup, the provider manages the keys, which is convenient but means the provider could technically access your data β so it is worth reading how your provider handles your data before you commit. For higher security needs, some organizations use client-side encryption tools that encrypt files before they are uploaded, so the provider never sees plaintext. However, this approach adds friction, because recipients need the same tool to decrypt the files.
Step 4: Evaluate End-to-End Encryption (S/MIME vs. PGP)
For the highest level of protection, end-to-end encryption ensures that only the sender and recipient can read the message content. Even the email provider cannot decrypt it. The two dominant standards are S/MIME and PGP. S/MIME uses certificates issued by a certificate authority, which makes it easier to manage in corporate environments but requires purchasing certificates for each user. PGP uses a web of trust model, where users exchange public keys directly, which is free but requires more manual effort.
S/MIME is generally the better choice for businesses because certificates can be centrally managed and are automatically trusted by most email clients. PGP is more common among technical teams and privacy advocates. Both methods encrypt the message body and attachments, but they do not encrypt the subject line or the sender and recipient addresses, because those are needed for routing. If you need to protect metadata as well, you would need a tool that operates outside standard email protocols.
Step 5: Train Your Team on Encryption Practices
Encryption is only effective if your team uses it correctly. Schedule a training session that covers how to recognize when a message requires end-to-end encryption, how to check that a certificate or key is valid, and what to do if a recipient cannot decrypt a message. Provide a simple decision guide: if the message contains personally identifiable information, financial data, or legal documents, use end-to-end encryption. For routine business correspondence, TLS is sufficient.
You should also establish a policy for handling encryption failures. For example, if a recipient's certificate has expired, the sender should contact them through a verified channel rather than sending the message in plaintext. Document these procedures in your employee handbook and review them during onboarding, alongside practical basics like out-of-office automation. A well-trained team reduces the risk of human error, which is the leading cause of data breaches.
How Email Encryption Works Technically
To make informed decisions, you need to understand the underlying mechanics. When you send an email, your client connects to your mail server over an encrypted TLS channel. The server then looks up the recipient's domain and attempts to establish a TLS connection with the receiving server. If successful, the message is encrypted during this hop. However, the message is briefly decrypted on each server before being re-encrypted for the next hop, which means the provider can technically read it.
End-to-end encryption solves this by encrypting the message on your device before it ever reaches the server. With S/MIME, your client uses the recipient's public certificate to encrypt the message. The recipient's client then uses their private key to decrypt it. With PGP, the process is similar, but keys are exchanged manually or through a key server. The critical difference is that the private key never leaves the user's device, so even the email provider cannot decrypt the content.
Authentication protocols like DKIM complement encryption by adding a digital signature. When you send a message, your server signs it with your domain's private key. The receiving server verifies the signature using your public key published in DNS. This proves the message wasn't altered in transit and that it genuinely came from your domain. Together, TLS, end-to-end encryption, and authentication protocols create a layered defense that protects your email from interception, tampering, and impersonation.
Explanation
Email encryption relies on asymmetric cryptography, which uses a pair of mathematically linked keys: a public key and a private key. The public key is shared openly, while the private key remains secret on the user's device. When a sender encrypts a message with the recipient's public key, only the recipient's private key can decrypt it. This is the foundation of S/MIME and PGP. RSA, the most common algorithm, typically uses 2048-bit or 4096-bit keys. A 2048-bit RSA key offers an estimated security level of 112 bits, which is considered adequate for most business use cases, while 4096-bit keys provide approximately 140 bits of security. Elliptic curve cryptography (ECC) is a newer alternative that offers comparable security with shorter keys β a 256-bit ECC key provides roughly 128 bits of security, which is why it is increasingly preferred for performance reasons.
TLS, by contrast, uses a hybrid approach. During the TLS handshake, the client and server use asymmetric cryptography to exchange a session key. Once both parties have the session key, they switch to symmetric encryption using AES (Advanced Encryption Standard). AES-256, which uses a 256-bit key, is the current standard for symmetric encryption and is approved by the U.S. National Security Agency for top-secret information. The handshake itself typically takes 1-2 round trips, adding roughly 100-200 milliseconds of latency to the first connection. Subsequent connections can reuse the session key through TLS session resumption, reducing the overhead to near zero.
For email specifically, the STARTTLS command upgrades a plaintext SMTP connection to an encrypted one. According to Google's transparency report, as of 2024, approximately 96% of inbound messages to Gmail are encrypted in transit, and about 94% of outbound messages are encrypted. However, that remaining 4-6% represents millions of messages sent daily without encryption. MTA-STS (SMTP MTA Strict Transport Security) addresses this by allowing domains to publish a policy that requires TLS. When a sending server encounters an MTA-STS policy, it must refuse to deliver if TLS is unavailable. As of early 2025, adoption of MTA-STS remains low, with only a small fraction of domains publishing policies, which is why choosing a provider that enforces TLS on its own servers matters.
Common Mistakes to Avoid
One of the most common mistakes is assuming TLS is always used. Many providers silently downgrade to plaintext if the receiving server doesn't support TLS. To prevent this, use a provider that enforces TLS and consider using MTA-STS (SMTP MTA Strict Transport Security) to instruct receiving servers to refuse non-TLS connections. Another mistake is neglecting to renew S/MIME certificates, which causes decryption failures and prompts users to bypass encryption.
A third mistake is sharing private keys or passwords through email. If you send a PGP private key or a password in the same channel as the encrypted message, you have defeated the purpose of encryption. Use a separate, secure channel like a password manager for key exchange. Finally, many businesses fail to monitor their DMARC reports, leaving them blind to spoofing attempts. Review these reports monthly and adjust your policy as needed β paying particular attention to the difference between transactional and marketing email streams, since they often authenticate differently.
How to Choose
Choosing the right encryption approach for your business depends on several factors. Use this decision framework to guide your choice:
Assess your data sensitivity. If you handle financial records, legal documents, or health information, you need end-to-end encryption. If your emails are routine business correspondence, TLS is likely sufficient.
Evaluate your team's technical skill. S/MIME is easier for non-technical teams because certificates are managed centrally. PGP requires users to manage keys, which can lead to errors.
Consider your compliance obligations. HIPAA, GDPR, and PCI DSS may mandate specific encryption standards. Check with your legal or compliance officer, and review your provider's terms of service, before choosing.
Check your provider's capabilities. NevTan Mail enforces TLS by default and provides guided SPF, DKIM, and DMARC setup. For end-to-end encryption, verify that your email client supports S/MIME or PGP with your provider's servers. If budget is a constraint, compare options in our guide to affordable business email for startups.
Plan for key management. Decide who will manage certificates or keys, how renewals will be handled, and what happens when an employee leaves. A clear key management policy prevents security gaps.
Start with a pilot group. Roll out end-to-end encryption to a small team first, gather feedback, and refine your procedures before expanding to the whole organization. This is the same staged approach behind why teams are switching to modern webmail.
FAQ
What is the difference between TLS and end-to-end encryption?
TLS encrypts the connection between email servers, protecting messages during transit. End-to-end encryption (S/MIME or PGP) encrypts the message content on the sender's device, and only the recipient can decrypt it. TLS protects against interception, while end-to-end encryption protects against both interception and provider access.
Does NevTan Mail support S/MIME or PGP?
NevTan Mail enforces TLS on all connections and provides guided SPF, DKIM, and DMARC setup. For end-to-end encryption, you can use S/MIME certificates or PGP keys with your email client, as NevTan Mail supports standard email protocols that work with these tools.
How long does it take to set up SPF, DKIM, and DMARC?
Setting up these records typically takes about 15 minutes. You copy the generated DNS records from your NevTan Mail domain settings and paste them into your DNS provider. DNS propagation may take up to 48 hours, but most providers update within a few hours.
Can I migrate from Gmail or Outlook without losing my encryption settings?
Yes. NevTan Mail supports OAuth migration from other providers, which imports your emails, contacts, and calendar. You will need to reconfigure your DNS records and re-issue any S/MIME certificates, but your historical messages remain intact.
What is MTA-STS and why should I use it?
MTA-STS (SMTP MTA Strict Transport Security) is a policy that tells receiving servers to refuse connections that do not use TLS. It prevents downgrade attacks where a message is sent in plaintext. Implementing MTA-STS requires publishing a policy file and a TLS certificate, which your provider may handle for you.
Is email encryption required by law?
It depends on your industry and location. Regulations like HIPAA, GDPR, and PCI DSS often require encryption for certain types of data. Even when not explicitly required, encryption is considered a best practice and can reduce liability in the event of a breach.
How do I know if my email was actually encrypted in transit?
Most email clients show a lock icon or a "security" indicator when a message was sent over TLS. You can also inspect the full message headers and look for the Received lines, which often include TLS or ESMTPS to indicate a secure connection.
What should I do if a recipient cannot decrypt my S/MIME message?
First, verify that the recipient's certificate is valid and not expired. If it is expired, ask them to renew it. If the certificate is valid, confirm that their email client supports S/MIME. As a fallback, you can send the message via a secure file-sharing link instead of an email attachment.
Secure Your Business Email With NevTan Mail
Securing your business email is not a one-time task but an ongoing commitment. The steps outlined in this guide β verifying TLS, configuring SPF, DKIM, and DMARC, and evaluating end-to-end encryption β form a solid foundation. However, the effectiveness of these measures depends heavily on your email provider. NevTan Mail is purpose-built for businesses that take security seriously. It enforces TLS on all connections by default, so you do not have to worry about silent downgrades to plaintext. The guided SPF, DKIM, and DMARC setup walks you through each DNS record, reducing the risk of misconfiguration. Your data is encrypted at rest with AES-256, and the platform is ad-free, meaning your email content is never scanned for advertising purposes.
NevTan Mail also integrates with the broader NevTan suite, including NevTan Cloud for application deployment and NevTan Sign for e-signatures, so you can manage your entire workflow in one connected ecosystem. Whether you are a small business sending contracts or a growing team handling sensitive client data, NevTan Mail gives you the tools to protect your communications without requiring deep technical expertise. Take the next step today: set up your custom domain at NevTan Mail and configure your DNS records. Your messages β and your reputation β depend on it.
