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:: SETLIFETIME ::
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Syntax: LT or SET(LIFETIME) <board> <range> [#] <days>

Sets the lifetime of one or more mails. A period of time has to be specified
in days beginning at the current day. The lifetime only can be changed by the
owner of the mail (sender or recipient). You can specify the "#"-sign, but
it is not necessary (only because of the compability to Thebox). If no
range is specified, SETLIFE relates to the last read mail. The range is
allowed between 0 and 999.

Examples:   SETL BAYCOM 5-10 30    Sets mails 5-10 in board BAYCOM to new
                                   lifetime of 30 days.
            SETL #100              Sets last-read mail to live 100 days.
                                   (Here '#' may NOT be ommited!)