I'm using Postfix to relay mail from my site to my mail server. Mail is received properly at my Gmail and Hotmail accounts - only Yahoo is the problem. The Yahoo mail headers state:
Received-SPF: none (mta1133.mail.mud.yahoo.com: domain of email@example.com does not designate permitted sender hosts)
In contrast, the Gmail headers state:
Received-SPF: pass (google.com: domain of firstname.lastname@example.org designates 74.50.xxx.xxx as permitted sender) client-ip=74.50.xxx.xxx;
Reverse DNS is set up correctly, as is my SPF record and domainkeys/dkim (both domainkeys and dkim show pass(ok) in the Yahoo mail headers).
Does anyone have any suggestions as to what I can do to solve the Yahoo problem (short of contacting Yahoo, as this is a brand new mail server)?