Road Runner 550 Unable to Relay Error

[paul at kcnetcare.com]

The FROM field is not equal to anything at kc.rr.com. That is incorrect
unless it's changing the past week. I know of several people who are using
the FROM field for @kcnetcare.com, @alexanderkey.biz, and @hotmail.com
e-mail addresses and their ISP is Road Runner.

Problem:
About 10% of the e-mail sent from two people is rejected and they get
bounce back messages with the 550 Unable to Relay message. I believe this
550 error message is originating at Road Runner SMTP servers.

Thanks,
Paul

> Paul Taylor wrote:
>> There are few users in a house paying residential rates yet they run a
>> home based business.
>> Outgoing SMTP is smtp-server.kc.rr.com
>> Incoming is not Road Runner, but their domain.
>> It's a 100Mbps wired LAN.
>>
>> It only happens to two of the users and it started two days ago.
>>
>> I called Road Runner and I got "Using another incoming POP3 other than
>> RR isn't supported and you're violating our terms anyway so we're not
>> helping you."
>>
>> I think it's their SMTP outgoing mail server because I seen a bounce
>> back when a user sent it to two different domains and the same bounce
>> back message had 550 error with both domains listed. What other MTA on
>> the Internet would see both outgoing mail at the same time other than
>> your own MTA?
>>
>> Any help would be appreciated.
>>
>> Thanks,
>> Paul
>
> I really think I could help but I'm so confused about what you're asking
>  that I don't know where to start. Could you rephrase the question?
>
> If your MTA sets the 'from' field to an address other than
> someone at kc.rr.com, smtp-server.kc.rr.com will reject it. I think it will
>  also reject if the request to send comes from outside their network. It
>  used to be that you could check your pop-server.kc.rr.com address first
>  and then the smtp-server would let you through. It also used to be that
>  smtp-server.kc.rr.com would let you log in before sending. It's been
> about six months since I had RoadRunner, though.
>
> Regarding what I think is a question about what MTA's are out there, I
> simply _love_ Mozilla Mail.
>
> --
> Jason Clinton
> I don't believe in witty sigs.