# The name of a mail exchanger, the forwards of whose domains we should
# ignore. For example, if one mail exchanger, mx1.example.com, has
# strict spam filtering, it may be acceptable to have remote forwarding
-# for domains that have mx1.example.com as their mail exchanger (MX
+# for domains that have mx1.example.com as their sole mail exchanger (MX
# record). In that case, you might want to exclude those domains from
# the report, by naming mx1.example.com here.
#
-# Given as a list, it can be used to exclude more than one mail
-# exchanger.
+# A forward will be excluded from the report only if *all* of its MX
+# records are contained in the given exclude list.
#
# Default: [] (empty)
#