I don't know the solution for you. However, I just looked in my yahoo email account which I really dont use and it had mail. It appears I won two million F's in the UK lottery. Their mail came through fine.

While filling out the paperwork to have it transfered into my bank I looked into the yahoo email options and do see you can add a filter to accept mail from anybody and have it moved to your inbox.
Perhaps that might work for you. Though I sort of have some doubts it will work.

I am curious who is her isp or what webmail does she send from ?

I better go finish giving them the rest of my bank account info so they can directly deposit my two million F's. See ya.

I sometimes bcc myself when I want keep a record. My Yahoo started diverting my own email that I send to me off to "bulk"

Is ISP the best/only way to reduce SPAM? That's the reason Yahoo and other ISPs block email, they think it is SPAM. Do all (most) ISPs offer SPAM blockers? I have Worldnet and have it set to save blocked email, and I go in periodically and check to see what's there (is this self defeating:>)? It works well, blocks something I want only rarely.

I use SBC and until I did away with bulk mail, I found a lot of my email there.

One thing is as Mikie said, you can unblock mail addresses.

Another thing is your aversion to allowing them into your email account. I did it a few times because my ATT/Yahoo account couldn't handle the overload of mail I receive, and my mailbox simply broke down several times and had to be rebuilt. While there is a limit, I receive so much at once and constantly that things periodically went wrong. I let them in and they fixed it each time, and I didn't lose any mail in the process. You don't have to give them your password. They can create a temporary password and then you change it back when they are finished.

Another thing is a Yahoo notice that was sent to their Plus users. I don't know if this applies to you because I don't know if you are a Plus subscriber and also have no idea if you use a third party email client like Outlook or IncrediMail or if your friends use one. You can decide for yourself if this is helpful to you at all. It really sounds more like the problem is on your friend's end. Ask her if she uses a third party client.

***********

"We have important news for Yahoo! Mail Plus subscribers who are
currently using our "POP" feature to send messages via external
email clients such as Microsoft Outlook, Outlook Express,
Thunderbird, Apple Mail, etc. (also called "SMTP access"). If you are
accessing your Yahoo! Mail Plus exclusively through our Web
interface, this message does not apply to you.

Recently, we saw an unexpected increase in traffic through the
servers dedicated to sending Yahoo! Mail Plus POP/SMTP messages. As a
result, some users have experienced varying delays in the delivery of
Yahoo! Mail messages sent via external email clients. We understand
that this has been frustrating, and sincerely apologize for the
inconvenience.

What Has Changed?

We have recently installed new servers to improve the performance of
Yahoo! Mail Plus SMTP access. We have spent the last several days
upgrading our hardware and restructuring the allocation of bandwidth
for these servers. We are confident these changes will resolve the
recent problems and increase our system's reliability.

Because of these improvements, the settings for your outgoing mail
server (SMTP) should change.

What Do I Need to Do?

To ensure that your email client is properly configured to access the
new outgoing mail servers (SMTP), please follow these brief steps:

1. Sign in to your Yahoo! Mail Plus account
2. Go to "Mail Options" --> "POP access" --> "View POP settings"
3. Review the updated settings in "POP Access Settings"
4. If needed, set your email client to the new server:
   plus.smtp.mail.yahoo.com

Or follow these detailed instructions to update your Mail Plus SMTP
settings:
http://help.yahoo.com/l/us/yahoo/mail/yahoomail/mailplus/pop/pop-35.html

Please check the Yahoo! Mail Blog for frequent updates on
this and many other Yahoo! Mail topics.

We deeply value and appreciate your continued business.

Thank you,

John Kremer
Vice President, Yahoo! Mail"

You mean > MAILER_DAEMON not > Mailer Demons.

Last year my emails to 2 Yahoo accounts got bounced by back to me. The problem was on Yahoo's end it cleared up after a while. Have your friend read why they got bounced or just have Yahoo take care of it as bestlawan said.

I have 2 accounts with Yahoo with no problems. The other day 1 of 2 messages sent (with OE) to the same Yahoo account got bounced with a DNS error.

Here is a link that might be useful: Yahoo mail

Yahoo is also blocking hundreds of our legitimate emails.

We are a small ISP with about 5000 small business users. Only a very small percentage of our users can send email to Yahoo, and even that is sporadic.

The only complaints that I have been receiving are those from our users that are sending emails to Yahoo users. All other email servers have no problem with our email server.

Hundreds of our users' legitimate emails are rejected daily with the following message:
421 Message from (208.66.56.9) temporarily deferred - 4.16.50. Please refer to http://help.yahoo.com/help/us/mail/defer/defer-06.html

Our email server tries resending deferred (queued) emails every 15, 30, 60, 90 and 120 minutes to Yahoo and Yahoo continues to defer all connections until our email server finally gives up on the delivery.

Our email server has never been blacklisted by any other mail server or any SBL organization.

I have filled out "Yahoo! Mail Delivery Issues Form" a few times. I get the following automated response message:
--------------------------------------------------------------------
Hello,

This is an automated message regarding your recent request for Yahoo!
Mail Customer Care support. We have received your message and willYa
respond within the next 48 hours with an answer.

Thank you for reaching out to us. We look forward to helping you!

Sincerely,

Yahoo! Customer Care

**Please do not respond to this message as no one will receive it.
--------------------------------------------------------------------------

But I never received a response from Yahoo and they continue rejecting our users' legitimate emails.

After reading many forums and blogs, it appears that they are doing the same thing to many other small ISPs and companies with their own email servers.

This practice can interrupt many legitimate business communications and hurts many small businesses.

Does anyone know if Yahoo has recently revised their email acceptance policy or implemented new policies on accepting emails from competitor hosting companies?