newinclude first writes the mailing list to list.tmp, and then moves it to list.bin. If there is any problem creating list.tmp, newinclude leaves list.bin alone.
newinclude always creates list.bin world-readable.
COMPATIBILITY WARNING: sendmail reads list directly; fastforward needs list.bin. sendmail's strategy is a disaster if you save list to disk at the same moment that sendmail reads it; the list will be truncated at a random spot, perhaps in the middle of an address. Furthermore, if the system crashes while you are writing list, list could be filled with all sorts of garbage.
COMPATIBILITY WARNING: newinclude does not support file or program deliveries in :include: files. You can use the secure delivery mechanisms described in dot-qmail(5) instead.
COMPATIBILITY WARNING: Versions of sendmail before V8 did not allow comments in :include: files.