My mail server has been getting the following error from Yahoo's mail servers since about a month: postfix/smtp: host g.mx.mail.yahoo.com[184.108.40.206] refused to talk to me: 421 4.7.1 [TS03] All messages from [my ip] will be permanently deferred; Retrying will NOT succeed. See http:// postmaster.yahoo.com/421-ts03.html
I have exchanged about 4 emails with Yahoo's support team. The first three seemed like automated messages, and the 4th told me that there is nothing they can do, but if I change my policies I can send them another email in 6 months. They also told me:
However, based on the information you have provided us, we cannot systematically deliver your email to the Inbox at this time. We suggest that you ask your users to set up a filter in Yahoo! Mail to ensure that they get your email messages in their Inbox.
The problem is that my email doesn't even get to their Spam folder. The server won't allow any connections.
I have never sent spam messages, not even newsletters. I only send emails for my new users so they can activate their account. I've also implemented DKIM and told Yahoo about this. I have checked my configuration with http://www.myiptest.com/staticpages/index.php/DomainKeys-DKIM-SPF-Validator-test and it reports that both SPF and DKIM are set up correctly.
What should I do? Basically, I'm losing new users every day. Any help will be appreciated.
P.S.: I apologize if this particular question has already been asked. I searched for it but didn't find it.