The following is a message from the Yahoo Postmaster Team
At around 12:30 PM PST this Tuesday (12/23), we suffered significant
connectivity issues on our MXes for yahoo.com and our other domains.
As we worked furiously to get our MTAs back to their normal state, we
were unavoidably deferring a lot of inbound SMTP connections from mail
servers trying to deliver messages to our users. We eventually were
able to stabilize our connectivity levels at around 3 PM PST.
We apologize for any delivery delays senders may have experienced
during this time. In the future, by posting to this group, we hope to
provide you timely(ier) updates that may impact your sending ability
to our users.