feedmail-enable-spray

feedmail-enable-spray is a variable defined in `feedmail.el'.
Its value is

nil

Documentation:
If non-nil, transmit message separately to each addressee.
feedmail normally accumulates a list of addressees and passes the message
along with that list to a buffer-eating function which expects any number
of addressees. If this variable is non-nil, however, feedmail will
repeatedly call the same buffer-eating function. Each time, the list of
addressees will be just one item from the original list. This only affects
the message envelope addresses and doesn't affect what appears in the
message headers except as noted.

Spray mode is usually pointless, and if you can't think of a good reason for
it, you should avoid it since it is inherently less efficient than normal
multiple delivery. One reason to use it is to overcome mis-featured mail
transports which betray your trust by revealing Bcc: addressees in the
headers of a message. Another use is to do a crude form of mailmerge, for
which see `feedmail-spray-address-fiddle-plex-list'.

If one of the calls to the buffer-eating function results in an error,
what happens next is carelessly defined, so beware. This should get ironed
out in some future release, and there could be other API changes for spraying
as well.

You can customize this variable.