How do I stop direct delivery of spam?

To prevent spam from being delivered directly to your server, we strongly recommend that you allow incoming mail traffic only from our IP address ranges.

For German customers:

Range: 83.246.65.0/24 with subnet mask 255.255.255.0, corresponds to 83.246.65.1 to 83.246.65.255
Range: 94.100.128.0/20 with subnet mask 255.255.240.0, corresponds to 94.100.128.1 to 94.100.143.255
Range: 173.45.18.0/24 with subnet mask 255.255.255.0, corresponds to 173.45.18.1 to 173.45.18.255

For European customers outside Germany:

Range: 83.246.65.0/24 with subnet mask 255.255.255.0, corresponding to addresses between 83.246.65.1 and 83.246.65.255
Range: 94.100.128.0/20 with subnet mask 255.255.240.0, corresponding to addresses between 94.100.128.1 and 94.100.143.255
Range: 185.140.204.0/22 with subnet mask 255.255.252.0, corresponding to addresses between 185.140.204.1 and 185.140.207.255
Range: 173.45.18.0/24 with subnet mask 255.255.255.0, corresponding to addresses between 173.45.18.1 and 173.45.18.255

For American customers:

Range: 83.246.65.0/24 with subnet mask 255.255.255.0, corresponding to addresses between 83.246.65.1 and 83.246.65.255
Range: 94.100.128.0/20 with subnet mask 255.255.240.0, corresponding to addresses between 94.100.128.1 and 94.100.143.255
Range: 185.140.204.0/22 with subnet mask 255.255.252.0, corresponding to addresses between 185.140.204.1 and 185.140.207.255
Range: 173.45.18.0/24 with subnet mask 255.255.255.0, corresponding to addresses between 173.45.18.1 and 173.45.18.255