Receiving "530 authentication required for relay" email replies

Posted on 2007-08-06
Last Modified: 2010-08-05
When emailing different companies, we receive intermittent bouncebacks.  These are few, about 1-2 a week that I am aware of, and many times from the same company (different people), but not always.

The error is:
The following recipient(s) could not be reached: on 8/6/2007 10:30 AM
            There was a SMTP communication problem with the recipient's email server.  Please contact your system administrator.
            < #5.5.0 smtp;530 authentication required for relay (#5.7.1)>

We are running SBS 2003 with Exchange.  I'm not knowledgeable in Exchange or email, and not sure where to start to diagonse this problem.  Thank you!
Question by:Repicheep
    LVL 104

    Expert Comment

    Do you send email email directly or via a smart host?
    If via a smart host then you need to speak to whoever server it is as it is their server that is rejecting your message.


    Author Comment


    I would say that we send email directly, but I'm not totally sure what you are asking.  I don't know what a "smart host" is or does.  (Would that be Alex Trebek).  jk

    We are using SpamSoap for incoming email only.  Outgoing should be going directly out.

    Thanks,   Steve
    LVL 104

    Accepted Solution

    Exchange can send email in one of two ways.
    Directly by doing DNS lookups.
    Indirectly via another SMTP server, which Exchange/Microsoft refer to as a smart host.

    If you run the Internet and Email connection wizard (or whatever it is called) there is an option in there about sending email through the ISPs server (or not). You need to see if that is completed or not.

    Otherwise it is looking at the SMTP logs for failures to see if you can find a pattern.


    Author Comment

    Simon,    Thanks for the direction.  I'm fairly sure we are not sending email through an ISP server, but checking the SMTP logs is a great idea.  I'll see what I can find in the logs when I return.

    LVL 1

    Expert Comment

    Forced accept.

    EE Admin

    Expert Comment

    Did the internet and email connection wizard do the trick for this?

    Featured Post

    Integrate social media with email signatures

    Is your company active on social media? Do you also use email signatures? Including social media icons in your email signature is a great way to get fans for free. Let all your email users know you’re on social media quickly and easily, in a single click.

    Join & Write a Comment

    Get an idea of what you should include in an email disclaimer with these Top 5 email disclaimer tips.
    In this video we show how to create an email address policy in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.:  First we need to log into the Exchange Admin Center. Navigate to the Mail Flow…
    The basic steps you have just learned will be implemented in this video. The basic steps are shown to configure an Exchange DAG in a live working Exchange Server Environment and manage the same (Exchange Server 2010 Software is used in a Windows Ser…

    728 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

    20 Experts available now in Live!

    Get 1:1 Help Now