Frequently Asked Questions


How does it work?

SMTP Sentinel acts as a Secure Email Gateway. The DNS MX record of your domain is changed, so it points to our SMTP Sentinel stacks. The email traffic is then redirected and we can filter unwanted emails out. The IP Address of your server (or the server which hosts your mailboxes) is the part of settings. The stack forwards the email directly to your server after all filters decided the email should reach your mailbox, and replays to the client when it receives the response. Your server should be locked down to accept only and only our IP Addresseses.


I do not know how to change DNS records. Can you help me?

Sure, we can and we are happy to help you. Do not hesitate and write us a message, so we can arrange the session.


Is SMTP Sentinel compliant with G Suite and Microsoft Office 365?

Yes, it is. SMTP Sentinel is fully compliant with G Suite and Microsoft Office 365.


How was the product tested?

SMTP Sentinel had been tested with the real domains for 18 months before we released it. Actually, we have not cease the testing domains because the results are very useful for our laboratory. The average amount of malicious emails is 5.000 per one month for one domain in the testing environment, mostly sent by spamming robots.


How reliable is the product?

The measured amount of spams blocked by SMTP Sentinel is 99.8%.


I have a special requirement. What shell I do?

Please, do not hesitate and contact our support. We believe that there is a solution on every problem. We encourage people to ask what they need to know.


I can't lock my SMTP server down. What now?

This case decreases the level of security, that's for sure. Although, you still have several possibilities. You can run your mailboxes without locking the server down. The change of receiving spams will be 50:50. Your service provider might have the possibility to lock the server down for our IP addresses. Or you can suggest to your provider to contact us. Or you can just simply run your own SMTP/IMAP/POP3 server. Many times it is cheaper and you have control over your services.


I'm an email services provider. What can you for me?

Please, do not hesitate and contact our support. We can build stacks dedicated to your services upon the contract.


Your servers are located in Germany. Do you plan to build SMTP Sentinel with IP addresses in other countries?

Definitely, yes. If you need one now, please, contact our support.


How will I pay for your products?

We offer monthly and yearly subscriptions for our products, excluding Penetration Testing product package. Yearly subscription contains 16% discount.


Can I unsubscribe from the product?

Yes. Anytime you wish. No fees apply.


Do you accept debit/credit cards?

We accept payments by cards only.
U.S. businesses can accept Visa, MasterCard, American Express, JCB, Discover, and Diners Club.
Australian, Canadian, European, Hong Kongese, Japanese, and Singaporean businesses can accept Visa, MasterCard, and American Express.


Do you accept PayPal?

No, not yet.


What should I do in case something went wrong with payment?


Is the Free product line really free?

Yes! And will be free as long as the company will last.