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.

Protection against blacklisting with Secure Mail Gateway from the Open Telekom Cloud

Three good reasons for the Open Telekom Cloud Secure Mail Gateway

Secure email marketing

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.

Easy to set up

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.

Maximum redundancy

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

The security mechanisms of Secure Mail Gateway at a glance

Scope of service

Good / Bad Gateway / Anti-spam

Good/Bad routing prevents you as the sender from permanently ending up on block lists of anti-spam providers. It first checks the email to be sent and assesses how likely it is to be considered spam. If the message is inconspicuous, it is sent via one of the "good" gateways. In the case of suspected spam, on the other hand, this suspicious email is sent via the "bad" gateway. Then there is a higher chance that the gateway will be put on a block list. Should this occur, the Support will check whether this can be remedied. However, there is no guarantee of this.

Virus scan

Secure Mail Gateways check all outgoing mails for viruses. Messages that contain a virus are rejected. The sender of the mail receives a Non Delivery Report (NDR).

Blacklist Monitoring

The automated blacklist monitoring checks the entries of ip blacklist service providers and informs you if your IP address has been included in a blacklist. For this purpose, a script is executed daily at 5 am. If it finds an entry, it informs the T-Systems service, which immediately, if possible, submits a deletion request to the respective blacklist provider.

Sender Domain Check

This function protects against misuse by checking whether the sender address is a valid domain before sending a mail. This means that the domain has a public MX record or at least a public A record that assigns an IP address to the address. Mails with sender addresses that do not meet these criteria are discarded.

Forced TLS*

A forced TLS communication can be set up based on the sender and recipient domain. For mails at these set up domains, the connection between the mail servers is then compulsory TLS encrypted. (In the event of an error, mails are then directly rejected or withheld if no TLS connection is established with the external mail server).

* for new clients

DKIM Signierung*

Based on the sender domain, DKIM signing can be configured for outgoing mails. (This can be requested via Cloud Handling Support).

* for new clients

For more information, refer to the user manual or contact Cloud Handling Support.

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

Step 1: Deposit DNS A-Record as SMARTHOST

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.

Step 2: Request your login details for authentication

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.

Relevante products

Any questions?

We will gladly implement your individual requirements – simply get in touch for free advice tailored to your needs.

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