530 authentication required for relay from one sender/company

Posted on 2007-08-06
Last Modified: 2013-11-30
One company attempting to email us is getting an intermittent bounceback

There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<c249.servername.LOCAL #5.5.0 smtp;530 authentication required for relay (#5.7.1)>

I'm not sure what their email system is but we're running exchange 2003.  I'm guessing this is an issue on their end because I'm not sure whey they would be attempting to relay through us, or it is an issue somewhere between them and us.  The server name in the error (c249.servername.local) is just their local server reporting the error, not necessarily the server that is denying the relay correct?  Also, is there some way to see if our server is the one possibly denying the relay, or to setup logging so that I can prove that their message isn't even getting to us when it bounces back, and hence we are not the ones denying the relay?

Question by:Tofu4679
    LVL 104

    Accepted Solution

    Unless they can prove it is YOUR server that is failing to allow the connection then it is nothing to do with you. The message is being rejected on the first hop, so if they are using a smart host to send email (for example through their ISP) then it is that server that is rejecting the message.

    LVL 1

    Expert Comment

    Forced accept.

    EE Admin

    Write Comment

    Please enter a first name

    Please enter a last name

    We will never share this with anyone.

    Featured Post

    Do email signature updates give you a headache?

    Do you feel like all of your time is spent managing email signatures? Too busy to visit every user’s desk to make updates? Want high-quality HTML signatures on all devices, including on mobiles and Macs? Then, let Exclaimer solve all your email signature problems today!

    Set up iPhone and iPad email signatures to always send in high-quality HTML with this step-by step guide.
    Not sure what the best email signature size is? Are you worried about email signature image size? Follow this best practice guide.
    This Micro Tutorial will demonstrate the easy use of Gmail embedding images in your email so the recipient of your email can view them in context.
    In this Experts Exchange video Micro Tutorial, I'm going to show how small business owners who use Google Apps can save money by setting up what is called a catch-all email address in their Gmail accounts. By using the catch-all feature, small busin…

    737 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    18 Experts available now in Live!

    Get 1:1 Help Now