Integration for Outlook in the browser, Gmail and mobile phone

Integration for Outlook in the browser, Gmail and mobile phone

Behind the scenes, we are working hard on our Intelligent Data Protection Platform. To keep you informed on all developments, we will share a (new or updated) feature every Friday in our “Feature Friday.”

Today we have the SMTP Relay Service, the "man in the middle", which ensures that emails are sent and delivered securely. How this exactly works and why this is important, you can read in this blog.


What is a SMTP Relay Service?

When emails are sent, things can go wrong along the way. In other words, there are obstacles between sending and delivery. For example, messages may not always be delivered or there may be blocks at certain IP addresses. This means that an email message gets stuck somewhere in the middle and can't be delivered to the recipient's inbox.

This can be annoying, because as a sender you have no control whether a message will be delivered or not. The same goes for the security with which messages are sent: with standard email, the level of security required from regulations such as the Dutch NTA 7516 can't be achieved. If you, as a sender, are not working with a secure email solution, an email will be sent without additional security. T

he risk is that your e-mail, which may contain sensitive information, may end up into the wrong hands.  A "controller" between sender and receiver can offer the solution here: that is what the SMTP Relay Service is.



How does the SMTP Relay Service work?

The email application you use, sends the email message and connects to the Relay Service. The sent email also comes with the email details: all this information is required by the Relay Service to determine how the message will be sent and to whom. This message can be sent directly to the recipient (“Message Delivery Agent”) or it takes several ways before it reaches the recipient's inbox.

The purpose of the Relay Service is simple. It ensures that all sent messages can be forwarded and arrive safely at the recipient:

SMTP Relay Service SmartLockr


So, the SmartLockr SMTP Relay receives an email and determines what needs to be done next. You, as the sender, won't see anything of this: the security is done entirely in the background. The convenience therefore remains with the user, because this does not disrupt work processes.

So, what exactly happens? There are a number of things that are picked up with the Relay Service:

  • A connection is made between the sender and recipient. It doesn't matter if both use different systems: the email message receives the correct information via the Relay Service in order to be delivered to the inbox of the recipient;

  • Does the email contain content triggers, set with the content policy within your organization? Then the Relay Service will add the appropriate security to this, by applying it in the background;

  • Are certain email domains on a so-called whitelist? Then SmartLockr will forward it without any adjustments. With blacklisted domains, the opposite happens: these will be blocked by the Relay Service.


The SmartLockr Relay Service will review an email message, to determine what to do based on pre-set settings. This allows emails to be sent correctly and delivered securely to the recipient.

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