Secure Email

Be Sure Your Email Is Safe, Private, and Legal

The CheckTLS Website lets you look at your email security from a casual glance to an in-depth scrutiny. It is for people who want to check that their email is safe, secure, and complies with all laws and regulations.

A subscription to lets you test hundreds or thousands of email targets. You list them in a "Batch" and we test it for you on-demand or on a schedule. Our Professional Services team can help you set this up.

We can also do one-time testing of a list of addresses for you. Contact Us for more information.

Busy pros should take a quick look at our Step By Step TLS Version or Step By Step Change Notice for testing tens to millions of email addresses.

Our commercial product, EmailSentry™ uses Outlook to check every email you send, giving you real-time assurance that your emails are safe, secure, and legal. It can be a significant, or even the only, piece of your HIPAA or GDPR compliance.

CheckTLS Isn't Free
The Website is only free for personal use. Using it for your job or organization requires a Subscription. Advertising revenue does not nearly cover the cost of the free site and subscribers do not see ads.

Just use common sense. If you test one thing one time for your company, you don't have to pay us -- just keep us in mind. But our logs show that one thing turns into two things turns into ten things. And we see and encourage you to come back and check those things again in a month.

Then provides real value and we think a $25 subscription is reasonable.

EmailSentry™ (Brochure)

EmailSentry is a commercial product licensed to companies for their employee use. It checks every recipient, every email, every time. It is an inexpensive, easy, and approved answer to HIPAA, GDPR, CCPA, PCI, and other email security compliance requirements. For many companies, it may be all you need. Sign up for a free trial.

Website: Check Your, or Any, Email System

See Show Me What CheckTLS Can Do.

Just Show Me The TLS Version!

You Are The Responsible Party

You are responsible for protecting the email that you send. We recommend you use the TLS encryption already built into your mail system, but you must check the recipient's email too. Ignoring security invites fines, civil and criminal legal action, and unwanted publicity.

Most email systems can encrypt email in compliance with US NIST, HIPAA, HITECH, GDPR, CCPA, PCI DSS, SOX, GLBA, SB1386, SEC 17a-4, NASD3010, FRCP, FINRA, etc. Test yours below.

Check How You Get Email (Receiver Test)
Confidence Factor: (displays here)

we do not keep or use your address, see our privacy policy

Check How You Send Email (Sender Test)

How you send email is more important than how you get email. When you send data via email, you are responsible for securing it until it gets delivered to the other side. If you email protected information, such as information subject to HIPAA, GDPR, or PCI, you must make sure the email is encrypted.

Click to send us a message to test. We will email you back the test results.

If the button does not work for you, or for more information about this test, use the menu choice //email/testFrom: or see the documentation at TestSender.

How Did You Do?

If either test shows any problems with your email, this site can help you find and fix them. See How To Use CheckTLS to get started.

If the two tests above, //email/testTo: ("TestReceiver") and //email/testFrom: ("TestSender"), show that your email can do the necessary encryption, then you have everything you need to meet your email transport security requirements and legal liabilities. See Secure Email Compliance Is Easy below for how to use what you have.

Show Your SSL Version Widget
Your LOGO Here    Show SSL Version
Address Version

(we do not keep your address)

Put Our Widgets On Your Site

Put the above TLS Version checker, or the "Get" and "Send" tests further above, or any other CheckTLS test, on your own site. We make the source code for widgets like these available for you to customize and build into your site.

Secure Email Compliance Is Easy

The tests show that your email can do proper email encryption. For compliance, you just have to make sure your email does that encryption on every email.

As long as encryption works on your sending end, and encryption works on the other person's receiving end, then Opportunistic TLS will encrypt and your email is compliant. The test above shows that your end works, and you know to re-test it regularly and especially after you make a change to it.

That leaves the other person's end. How can you be sure that their end is "encryption ready" every time you send to it? Do that by testing the other person's end regularly (e.g. daily), or, better yet, on every email with the CheckTLS Outlook Add-in.

See Secure Email Compliance for more information. You don't need to buy any hardware or pay for an online service: your email already has everything you need! And if you already have hardware or an online service, CheckTLS is an easy way to regularly check that it's working, and help you enforce your SLAs.

Secure Email Compliance In Outlook

EmailSentry puts CheckTLS email compliance (HIPAA, GDPR, CCPA, PCI-DSS, etc.) into Outlook. No technical knowledge required. No extra steps, equipment, or changes to your network.


The Red Arrow

Email has three parts: your end, their end, and the Internet in the middle. You control your end, they control their end, but that middle part, the Internet, is "uncontrolled".

CheckTLS is about the red parts of the picture. We help you secure and test the parts of your email system that touch the Internet. Many places ignore these areas because it's too hard, or they don't know how to get started.

And no matter how sophisticated your Internet touching systems are, they should be verified and regularly tested.

The government (NIST) released Special Publication 800-177 (Revision 1) entitled Trustworthy Email (nice overview at Nextgov) that shows how CheckTLS can help.

No matter your security level, this site will help.

Yes, There is More

And, back to the Red Arrow. We realize that your part, your green arrow above, has data encryption at rest, data retention, data protection, data destruction, and other ramifications.

We are just about the Red Arrow, but we do it better than anyone else. CheckTLS is the only site that can:

Commercial Services


We are part of the security policies and operations of some very large and prestigious financial institutions, health care systems, insurance companies, and law firms. Why? Two reasons: our tests work, and we save them money!

Secure Your Company Email

You can use CheckTLS instead of expensive email appliances or on-line email services to meet internal security requirements, contractual security requirements, and government security requirements. One less moving part in your email chain and one less expense. Our tests are a very inexpensive answer to PHI (HIPAA/HITECH), GDPR, PCI-DSS, PII, US NIST requirements.

If you already have extra in-line or on-line email security, CheckTLS can verify they're working and monitor them to be sure they keep working. A few extra bucks a month to make sure all that sophisticated stuff is working.

Protect Your Company from Your Business Partners

Use CheckTLS to make sure your trading partners are secure enough to do business with you. As part of your new vendor and new customer process, verify that their email scores a Confidence Factor℠ of 90 or above on our //email/testTo: ("TestReceiver") test.

Broadly Applicable

Whether you are a small shop that needs something simple and low cost, a medium business that needs to beef up security to meet increasing scrutiny by your trading partners, or an enterprise organization that wants some oversight of many security facets, CheckTLS can solve many of your security challenges faster, easier, and at significantly less cost.


Our tests are non-invasive, non-intrusive, and non-obtrusive. They require no changes to your or any other system. They cause no extra processing and should not trip any security alarms.


Our tests are simple, open, and proven. We keep up with technology and security trends and requirements, and we are constantly adding features and functionality. CheckTLS does over 4 million tests per month, and since we started 12 years ago we have done some 100 million tests.

We research all questionable results, and we welcome feedback and suggestions. You can turn up the detail and audit everything we do.

Business Benefits
Business Users Have Priority

Sleep better knowing someone else is watching over your email.

Email and Cloud Tools