Is the format of the configuration file set, or can you make it whatever you want it to be? If you can choose the file format then you can use one of the many Config modules in CPAN.

If you do not have any choice over the configuration file format then consider using a hash to store the configuration values:

my %configOptions = (
  To => Header::To (),
  From => Header::From (),
  ...
  );

# code to read configuration file
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