Hi all,

Since yesterday, our emails to two different particular recipients are bounced back right away.

Undeliverred message: Diagnostic-Code: smtp; 550 failed to meet SPF requirements

Another message of undeliverred mail in deferred queue: 453 please see http://spf.pobox.com/why.html]SPF: Why.html? Sender=........

Please advise this! Thanks in advance!