SYNOPSIS

 my $index = Mail::Box::MH::Index->new;
 $index->read(...)
 $index->write(...)

See SYNOPSIS in Mail::Reporter

DESCRIPTION

Message folders which store their data in one single file per message are very inefficient for producing subject overviews and for computing message threads. The Mail::Box::MH::Index object is able to store and read a the headers of a set of Mail::Box::MH::Message messages which are part of a single Mail::Box::MH folder in one file.

When the Mail::Box::MH::Index functionality is enabled by specifying Mail::Box::MH::new(keep_index) when opening a folder, the index file is automatically read. When the folder is closed, a new index file is created.

Special care is taken to avoid problems which occur when the user changes or removes message files without updating the index. If the index is not trustworthy it will not be used (costing some performance for the reader of the folder).

See DESCRIPTION in Mail::Reporter