What is SSL in email?
Definition
SSL in email is the encryption of the connection that carries your messages between your device and a mail server, or between mail servers. Today the protocol used is TLS, the successor to SSL.
- Category
- Security
- Also called
- SSL email, email encryption in transit, TLS in email
- Last updated
Reviewed by Anthon Wansland
Head of Product & Co-Founder
Serus is a privacy company with paid tools to find and remove your personal data. This page is free and based on official sources.
Sources checked: csrc.nist.gov
Last verified against the official page:
When your email app connects to a mail server, it can do so over a plain connection or an encrypted one. SSL (Secure Sockets Layer) was the original way to encrypt that connection. It has been replaced by TLS (Transport Layer Security), but mail settings still often say "SSL" out of habit. NIST's glossary describes TLS as a security protocol that provides privacy and data integrity between two communicating applications, defined in RFC 5246 and RFC 8446.
Where it is used
TLS can protect each step email takes. For sending, the SMTP option STARTTLS tells a client that TLS is available. For reading mail, POP3 can use TLS through the STLS command, and encrypted IMAP runs over port 993. NIST's draft guidance on trustworthy email (SP 800-177 Rev. 1) lists TLS among its recommendations for email transmission security, saying it uses an encrypted channel to protect message transfers from man-in-the-middle attacks.
What it does not do
TLS protects the message while it travels between two points. It does not hide the message from the mail provider, and it does not protect it once it is stored in your inbox. Each hop needs TLS for the whole path to be protected, so a message can still pass over an unencrypted link if one server doesn't support it. This is different from end-to-end encryption, where only the sender and recipient can read the message.
A typical example
In your email app's account settings you will see a choice such as "SSL/TLS" or "STARTTLS" next to the server port. Choosing it means your password and mail are sent over an encrypted connection rather than in the clear, which matters most on shared or public Wi-Fi.
How to protect yourself
- 1
Choose SSL/TLS in your email account settings
When setting up an email app, pick the SSL/TLS or STARTTLS option for both incoming and outgoing servers instead of no encryption.
- 2
Use secure ports
Encrypted IMAP runs over port 993. If your app offers an unencrypted option on a different port, don't use it.
- 3
Don't send secrets by ordinary email
TLS only protects the message in transit. Avoid emailing passwords, ID numbers or card details, because the message can still be read at either end.
- 4
Protect the account itself
Encryption in transit doesn't help if someone has your password. Use a unique password and two-step verification on your email account. Serus monitors breach databases and alerts you when your email appears in one.
See where your personal data is exposed
Serus finds it on data brokers and people-search sites and removes it.
Frequently asked
Is SSL the same as TLS?
TLS is the newer version of SSL. People and settings menus still say SSL, but modern connections use TLS.
Does SSL make my email private?
It encrypts the connection while the message travels. It does not stop your email provider from reading it and does not protect stored mail. For that you need end-to-end encryption.
What is STARTTLS?
STARTTLS is an SMTP option that tells a client TLS is available so the connection can be upgraded to an encrypted one, according to NIST's guidance on trustworthy email.
What is the difference between SSL and TLS in email settings?
In most email apps they refer to the same idea, an encrypted connection to the mail server. Choose the TLS or SSL/TLS option when it is offered.
Sources
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