Local

Local lookup lists are static lists that are kept entirely in memory. They are defined directly in the configuration file and are useful for storing small amounts of static data that do not change often. lookup lists are used from expressions or Sieve filters and their contents can be defined directly in the configuration file or loaded from local files or from remote HTTP resources.

Configuration

Local lookup lists are specified in the configuration file under the lookup.<name> section, where <name> is the unique identifier for the lookup list. Keys under the lookup.<name> section define the entries in the lookup list, where the key is the lookup key and the value is the lookup value.

For example, to create the allow-list-domain lookup list with the keys example.com and example.org, the configuration would look like this:

[lookup."allow-list-domain"]
example.com = true
example.org = true

It is also possible to use glob patterns in the keys to match multiple entries. For example, to create an lookup list that matches all subdomains of example.com and all mail exchangers of example.org, the configuration would look like this:

[lookup."allow-list-domain"]
"*.example.com" = true
"mx?.example.org" = true