My wife hasn't been able to send *or* receive email, via the web or via POP3. When she tries to log into the Verizon/Yahoo mail web page she gets "Temporary Error 16" and when she tries to send mail from her OSX Mail application, it never leaves, even though Mail says it is connected to outgoing.yahoo.verizon.net
Worst, when I try to send her mail from another Verizon account, it comes back as undeliverable due to an SMTP error:
{edited for privacy}