Yahoo blocks the IP Address

[jocelynlum]

This message was created automatically by mail delivery software.
A message that you sent has not yet been delivered to one or more of its
recipients after more than 24 hours on the queue on xxxxxxx

The message identifier is: xxxxxxxxxxxxxxxxxxx
The subject of the message is: xxxxxxxxxxxxxxxxxxxxxx
The date of the message is: Wed, 30 Jul 2014 10:30:58 +0800

The addresses to which the message has not yet been delivered are:

xxx@yahoo.com
Delay reason: SMTP error from remote mail server after MAIL
FROM:<xxxxxxx>
host mta5.am0.yahoodns.net [xxx]: [TS03] All
messages from xxxxxxxxx will be permanently deferred; Retrying will NOT
succeed. See http://postmaster.yahoo.com/421-ts03.html


No action is required on your part. Delivery attempts will continue for some
time, and this warning may be repeated at intervals if the message remains
undelivered. Eventually the mail delivery software will give up, and when
that happens, the message will be returned to you.

 

[EQ Admin]

What is the IP address of your outgoing mail server?

Check the logs, is it being used to spam?

Likely sources of spam include open relays, compromised accounts with access to smtp authentication, compromised web sites, and backscatter.

If there is a lot of legitimate email coming from the server try separating your best email senders from any bulk mailers such as company newsletters and other mailing list traffic.