Unfortunately, spammers have the possibility to deliver messages directly to your mail server without checking through our filter and causing spam. Therefore, you should configure your mail server to accept only messages that have been checked by our filter.
To ensure that only messages from the EuropeanMX cloud are accepted on your mail server, it is best to use the address "delivery. antispamcloud. com" for approval. This hostname contains all active IPs and can be used as reverse DNS for the IPs that deliver the hostname. For redundancy reasons, we have divided our EuropeanMX cloud into different data centers and networks. As we regularly extend the EuropeanMX cloud, it is possible that new IPs will be added from time to time. A list of IPs can be found on our website https://europeanmx.eu/de/mxstatus
Please make sure that your firewall does not block communication via port TCP 53.
If this is not possible on your mail server, you can configure the target server to listen to an alternative port (e. g. 2525 instead of 25 by default). This special port can then be entered in the customer account in the domain details of the route for the destination server.