Hello,

We have received reports that some senders are seeing intermittent IP blocks
when sending to Yahoo! Mail, with the SMTP error message from us citing that the
block was due to a Spamhaus listing -- e.g., "553 5.7.1 [BL21] Connections not
accepted from IP addresses on Spamhaus PBL." (See our full list of SMTP error
messages at http://postmaster.yahoo.com/errors/ .)

If your IPs are currently not listed on any Spamhaus blocklist but you are
seeing this error, please be assured that we are looking into the matter. We
shall post an update once we have resolved the issue.

Thank you for your patience.

Regards,

The Yahoo! Mail Postmaster Team