Resources unavailable temporarily

Yahoo and Postfix 26
If you’re getting “temporarily deferred” Postfix log entries when trying to send mail to Yahoo! that look like this: host[] refused to talk to me: 421 4.7.0 [GL01] Message from ( temporarily deferred - 4.16.50. Please refer to or status=deferred (host[] said: 451 Resources temporarily unavailable. […]

How-To: Postfix configuration to reduce Yahoo temporary deferrals using Transport ...