| pv -s ${SIZE} -p -t -e - \
| mboxgrep ${HEADER_ONLY} -i "${RE_PREFIX}${PATTERN}" \
| mboxgrep ${HEADER_ONLY} -v '^Subject:.*SPAM' > ${RESULT_MBOX}
| pv -s ${SIZE} -p -t -e - \
| mboxgrep ${HEADER_ONLY} -i "${RE_PREFIX}${PATTERN}" \
| mboxgrep ${HEADER_ONLY} -v '^Subject:.*SPAM' > ${RESULT_MBOX}