Need email server aid

[Christopher Chan]

>> Apr 21 17:01:40 ckenterprises postfix/smtpd[24088]: NOQUEUE: reject:
>> RCPT from mail.ckent.org[66.254.194.29]: 554 5.7.1
>> <addr at dest.com>: Relay access denied; from=<device at ckent.org>
>> to=<addr at dest.com>  proto=SMTP helo=<ckent.org>
>> Apr 21 17:01:40 ckenterprises postfix/smtpd[24088]: disconnect from
>>
>
>
> If I remember correctly, reject_unknown_sender_domain requires a
> working DNS, A record, and maybe MX for the connecting IP. You might
> try re-ordering that section, or just remove that as a test (be sure
> to do a postfix reload).
>

That's not a unknown sender domain problem, that's postfix doing the 
right thing. I suspect the OP forgot to enable authentication on his 
mail client.