4. Mail Filtering Language

The mail filtering language, or MFL, is a special language designed for writing filter scripts. It has a simple syntax, similar to that of Bourne shell. In contrast to the most existing programming languages, MFL does not have any special terminating or separating characters (like, e.g. newlines and semicolons in shell)(12). All syntactical entities are separated by any amount of white-space characters (i.e. spaces, tabulations or newlines).

The following sections describe MFL syntax in detail.

Footnotes

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There are two noteworthy exceptions: require and from ... import statements, which must be terminated with a period. See section Require and Import.