My primary SMTP server does NOT require authentication, and does NOT require the "from" email address to be associated with a particular domain.
Most of the time, I send mail from whatever address I am using for a particular correspondent with no problem at all. Emails get to where they're going and don't bounce back as long as they're valid addresses.
Recently when I send email to those email I sent before, the email gets bounce back with " 550 5.7.1 <firstname.lastname@example.org>...Relaying Denied. IP name lookup failed [220.127.116.11] "
What gives? What settings need to be changed?
I'm using MS Outlook 2007