Stalwart Mail Server offers a flexible configuration system through the use of rules. These rules, which consist of single or nested if blocks, provide system administrators the ability to tailor the server behavior based on contextual variables such as IP address, sender, recipient and more. Rules can be applied to most parameters of the configuration file and are represented using nested TOML structures containing if, else, all-of, any-of and none-of attributes.
Comparators are functions that evaluate the contents of a variable against a specified value and return a boolean result. The following value comparators are available:
📄️ Logical expressions
Logical expressions enable the evaluation of one or multiple conditions using boolean operations such as AND, OR, and NOT. The following logical comparators are available: