About a month ago I started having trouble sending email from my sub account. It will not send at all. I am using Thunderbird and XP Pro. I have no problem sending email from the primary account.

This message pops up:

"An error occured while sending mail. The mail server responded From address not verifiedl; see http:help.yahoo.com/us/yahoo/mail/ original/ manage/ sendfrom-07.html. Please verify that your email address is correct in your Mail preferences and try again."

Then I try again and get this:

"Sending of message failed/ The message could not be sent because connecting to SMTP server smtp.att.yahoo.com failed. The server may be unavailable or is refusing smtp connections. Please verify that your smtp server setting is correct and try again, or else contact your network administrator."

I have not changed any settings since before I got these messages.
I have found threads on the internet about this problem, but I don't know if anyone ever found a solution. I can not find any answers on yahoo's site that help.

I also have an email account on another desktop that I use to send email to members of an organization. This email account has been giving me the same problem, however it will eventually send the email after several tries. But it seems like it is getting worse with that email account.

Any help would be appreciated.