Views:
Block lists stop messages from the blocked senders, bypassing IP-level filtering. Block lists are not applied to your MTA, but you can set up additional blocked or approved senders, or perform additional filtering at your MTA. The trade-off for bypassing IP filtering are the additional resources that are needed to process, filter, and store the higher levels of spam messages that would otherwise have been blocked. When using the block lists, you may experience lower overall spam catch rates.
In the case of a standard reputation (Known Spam Source List) service lookup, the order of the evaluation hierarchy is:
  1. Approved IP
  2. Blocked IP
  3. Approved country
  4. Blocked country
For dynamic reputation (QIL) service lookup, the customer-defined “blocked policy lists” (IP, Country) are ignored; only the approve lists are checked. Otherwise, the order of policy lookup (first IP, then country) is the same as for standard reputation (Known Spam Source List) service.

Procedure

  1. Go to https://servicecentral.trendmicro.com/en-us/ers/.
  2. Go to Policy → Blocked Lists.
  3. Under Countries/Regions, select a country and click Add >.
    The selected country moves to the Blocked section.
  4. Under IP addresses, specify IPv4 or IPv6 addresses and click Add >.
    The IP address moves to the Blocked section.
    When specifying the IP address, you can use the following:
    • Standard IPv4 format: 123.123.123.123
    • IPv4 IP address range in CIDR notation: 123.123.123.123/24
      Note
      Note
      Avoid specifying the same CIDR range in the Approved and Blocked lists, as unexpected results might occur. If required, the approved CIDR range must be less than or equal to the blocked CIDR range.
      For example, avoid specifying 172.31.15.164/30 in the Approved list and 172.31.15.164/31 in the Blocked list
    • Standard IPv6 format:
      • 2001:0db7:85a3:0000:0000:8a2e:0370:7334
      • 2001:db7:85a3:0:0:8a2e:370:7334
      • 2001:db7:85a3::8a2e:370:7334
  5. Click Save.