I have multiple emails on queue due to some "DomainKey", and whenever I try sending an email, I get this: Your message did not reach some or all of the intended recipients. Subject: asdf Sent: 4/16/2011 1:29 PM The following recipient(s) cannot be reached: [EMAIL TAKEN OUT] on 4/16/2011 1:29 PM Server error: '553 sorry, that domain isn't in my list of allowed rcpthosts (#5.5.3 - chkuser)' I'm running on Kloxo, which I installed on my VPS using a tutorial - I am otherwise completely clueless. Any ideas on how to correctly set up the mail server so mail can be sent and received properly? Thanks.