#
# Some MX servers are still allowing underscore inside of the domain part
# of the email address.
# Meanwhile, DNS servers forbidden usage of the underscore by default
# nowadays.
#
# Until 09.10.2022 libeav had allowed underscores by default; now they
# are forbidden. The behaviour may be changed at compile time by
# passing the option LABELS_ALLOW_UNDERSCORE = ON|OFF to 'make' command.
#
# Note that the idnkit2's function
#   idn_res_encodename(ctx, IDN_ENCODE_REGIST, ...)
# does NOT allow underscores too, but libeav is using this function only
# when RFC 6531 mode is on.
#
underscores@old_days.example.net
