rm "${MH_TEST_DIR}/Mail/draft"
# check -append
-sed -s '4a\Nmh-test:' "${MH_TEST_DIR}/Mail/inbox/1" >"$expected"
+sed -e '5a\
+Nmh-test:' "${MH_TEST_DIR}/Mail/inbox/1" >"$expected"
anno 1 -component Nmh-test -append
sed -e 's/^Nmh-test:.*/Nmh-test:/' "${MH_TEST_DIR}/Mail/inbox/1" >"$actual"
check "$expected" "$actual"