Try these settings:
ALLOW RELAY - NOBODY and
REQUIRE AUTH MATCH EQUAL E-MAIL ADDRESS:
Notice the two variables in the SMTP BANER LINE?
They MUST be included in the SMTP BANNER, POP BANNER, and IMAP banner as well. or YAHOO will either block, or limit the number of e-mail messages you can send during the day.
To quote Gomer Pyle, "SUPRISE . . . SUPRISE . . . SUPRISE , , , "
This was quietly implemented last FEBRUARY, and no one from YAHOO said anything, they just started bouncing messages. They did insert a cryptic message bounce and link in the header, but you had to search to find it and then open their Postmaster Portal page to search for the information you needed.
Once we added the banners, all mail to YAHOO started flowing, immediately, as if we'd never been blocked or slowed down
Here's our COMPLETE BANNER, which is added to the message headers of all SMTP transactions and also added to our logs. It helps us a great deal when we are attempting to find a spammer or someone's account which has been compromised.
"#HostName# #TimeUTC# UTC | SmarterMail Enterprise Version 15.4.6151.26341"
Phonr: (773) 491-9019
Phone: (224) 444-0169
E-Mail and DNS Security Specialist
Network Security Specialist
Customer Service Portal: https://portal.chicagonettech.com
Security Blog: http://networkbastion.blogspot.com/
Web and E-Mail Hosting, E-Mail Security and Consulting