An update for the y!groups mailer list October 16, 2007:
current complete list as of October 16, 2007:
Adding these addresses to your whitelist helps ensure that client
email is not blocked due to false positives from filters.
For more information about how to read these address ranges,
In short, an address block like 188.8.131.52/24 means
all the addresses from 184.108.40.206 through 220.127.116.11
should be allowed to send mail as these are Yahoo! Groups
outbound mail servers.