Feb 23 15:13:05 dell postfix/smtp[29868]: 734C01A1DB4: host f.mx.mail.yahoo.com[209.191.88.247] refused to talk to me: 421 Message from (#.#.#.#) temporarily deferred - 4.16.50. Please refer to http://help.yahoo.com/help/us/mail/defer/defer-06.html

I of course checked out the link, but it was no help. Someone suggested that a reverse DNS lookup does not point to the domain I am sending email with. It does not as I am using a cable Internet connection and it resolves to their host name. (342874.il.chicago.rcn.net or similar) What do I enter into my DNS to make a reverse lookup find mydomain.com?