Sortm sorts the specified messages in the named folder according
to the chronological order of the \*(lqDate:\*(rq field of each message.
The `-verbose' switch directs sortm to tell the user the general
actions that it is taking to place the folder in sorted order.
The `-datefield\ field' switch tells sortm the name of the field to
use when making the date comparison. If the user has a special field in
each message, such as \*(lqBB-Posted:\*(rq or \*(lqDelivery-Date:\*(rq,
then the `-datefield' switch can be used to direct sortm which
field to examine.
The `-textfield\ field' switch causes sortm to sort messages
by the specified text field. If this field is \*(lqsubject\*(rq, any
leading "re:" is stripped off. In any case, all characters except
letters and numbers are stripped and the resulting strings are sorted
datefield-major, textfield-minor, using a case insensitive comparison.
With `-textfield\ field', if `-limit\ days' is specified, messages
with similar textfields that are dated within `days' of each other
appear together. Specifying `-nolimit' makes the limit infinity.
With `-limit 0', the sort is instead made textfield-major, date-minor.
