Open Telekom Cloud for Business Customers

Secure Mail Gateway

Avoid unwanted entries in spam blacklists

For customers who do not want to operate their own mail server in the Open Telekom Cloud, we offer free anti-virus and anti-spam functionalities for your outgoing email traffic with the Secure Mail Gateway. The service thus prevents your sender IP from being put on a blacklist of unwanted senders by anti-spam databases and from getting blocked. In this way, the Secure Mail Gateway protects your reputation and ensures secure delivery of your customer mailings.

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Three good reasons for the Open Telekom Cloud Secure Mail Gateway

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Secure email marketing

Not only the anti-virus and anti-spam function ensures secure email marketing. In addition, the Sender Domain Check protects against misuse and the blacklist monitoring alerts you to entries in blacklists.

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Easy to set up

The Secure Mail Gateway can be set up in just two simple steps. If you already operate a mail server outside the Open Telekom Cloud, you can continue to operate it almost unchanged.

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Maximum redundancy

To ensure the highest level of reliability, the Secure Mail Gateway consists of six servers distributed across Frankfurt, Munich and Magdeburg. There are two systems in each location.


Use the Secure Mail Gateway for secure and efficient customer mailings


How Secure Mail Gateway prevents entries in spam blocking lists

 Graphic with sender around receiver to show Secure Mail Gateway in the cloud

Scope of service

Good / Bad Gateway / Anti-Spam

Virus scan

Blacklist Monitoring

Sender Domain Check

Forced TLS*

DKIM Signierung*


Easy to set up: How to activate Secure Mail Gateway in just two steps

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1. Deposit DNS A-Record as SMARTHOST

Store the following DNS-A record as SMARTHOST in the mail server or in your mail application: (for new clients) (SPF) (for new clients)

Port 25 is available for the connection of systems from the Open Telekom Cloud to the SMARTHOST. Other ports are not active on the secure mail gateway for mail acceptance.

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2. Request your login details for authentication

You can now authenticate as a user to prevent entries in blacklists and increase the security of your email marketing through TLS authentication. Your username and password are provided by Cloud Handling Support. New customers will then receive a registration email from Secure Mail Gateway, which you can use to assign your own password.


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