MBOX
if (mp->m_flag & MBOX)
dot->m_flag |= MTOUCH|MBOX;
mp->m_flag &= ~(MPRESERVE|MSAVED|MBOX);
mp->m_flag &= ~MBOX;
holdbit = autohold ? MPRESERVE : MBOX;
nohold = MBOX|MSAVED|MDELETED|MPRESERVE;
if (mp->m_flag & MBOX)
if (mp->m_flag & MBOX)