Yahoo is filtering/blocking my emailYahoo tracks all connections made from outside mail servers and sometimes they will put a cap on how much mail you can send their clients if they think you are spamming, or just sending a lot of email to them in general.
One way around this is to let Yahoo know your intentions by filling out the following form:
http://help.yahoo.com/l/us/yahoo/mail/postmaster/bulk.
html?from_url=http://help.yahoo.com/l/us/ yahoo/mail/original/abuse/abuse-58.
html You should include the from email address you are using to send through Email System as well as the private IP address which can be found within your account settings towards the bottom of the page.
Other Useful Yahoo Links(Main postmaster link)
http://help.yahoo.com/l/us/yahoo/mail/postmaster/
(Best Practices when sending to Yahoo)
http://help.yahoo.com/l/us/yahoo/mail/postmaster/postmaster-15.
html (Getting your email to the inbox not junk/bulk folder)
http://help.yahoo.com/l/us/yahoo/mail/postmaster/postmaster-02.
html