I have seen Mike K4PI post that before but I have used yahoo for years with no issues.
Most if not all of the bounces were from people who have been subscribed for years.
Everything seems ok now so hopefully we are good. I suspect some issues at contesting.com
Most bounces are from users who forget what email that are subscribed with and try to post from a different email. That is not the case this time.

73 Gordon N4LR

From: Kevan Nason <knason00@gmail.com>
To: Gordon Macie <gmacie@yahoo.com>
Sent: Tuesday, November 6, 2012 10:48 AM
Subject: Re: [SECC] Test - Maybe something wrong with mailing list

Just to let you know I received this. Was told that there are
sometimes issues when using things like gmail (me) and yahoo.
Apparentlly the server software looks at those addresses as "aliases"
instead of a legitimate email address and causes problems.

Kevan
N4XL

On 11/6/12, Gordon Macie <gmacie@yahoo.com> wrote:
> Just received about 10 bounces in 1 minute. They look like
> legit calls/ messages. Never seen this before, hopefully it is just a burp
> by the server.
>
> Gordon N4LR