I have recently moved all of my websites to a new (and more secure server). Out of 50 customers, 2-3 are having email issues, specifically with sending emails within the same domain and to domains on the same server.

Here's a sample error message:

Diagnostic information for administrators:

Generating server: AMXPR04MB247.eurprd04.prod.outlook.com

[email protected] babcom-h2.lnc.net Remote Server returned '550 Authentication is required for relay'

Original message headers:

Received: from DB3PRD0411HT001.eurprd04.prod.outlook.com ( by AMXPR04MB247.eurprd04.prod.outlook.com ( with Microsoft SMTP Server (TLS) id 15.0.800.7; Fri, 15 Nov 2013 08:54:25 +0000 Received: from [] ( by pod51014.outlook.com ( with Microsoft SMTP Server (TLS) id 14.16.371.2; Fri, 15 Nov 2013 08:54:24 +0000 From: Franklyn Nevard Content-Type: multipart/alternative; boundary="Apple-Mail=_2340A5CF-1977-490C-A345-7D19967ACFFE" Message-ID: MIME-Version: 1.0 (Mac OS X Mail 7.0 (1822)) Subject: Re: Hosting invoice from MoonSpace Date: Fri, 15 Nov 2013 08:54:21 +0000 References: <[email protected]> To: Pat Dobson In-Reply-To: <[email protected]> X-Mailer: Apple Mail (2.1822) Return-Path: [email protected] X-Originating-IP: [] X-Forefront-PRVS: 0031A0FFAF X-Forefront-Antispam-Report: SFV:NSPM;SFS:(71364002)(51704005)(199002)(189002)(24454002)(81342001)(74366001)(56816003)(16601075003)(76786001)(16236675002)(65816001)(63696002)(15202345003)(53806001)(82746002)(69556001)(15974865002)(81542001)(4396001)(80022001)(76796001)(51856001)(77156001)(15975445006)(87266001)(87286001)(66066001)(46102001)(85306002)(36756003)(74706001)(83716003)(83322001)(83072001)(71186001)(57306001)(33656001)(512874002)(74876001)(512934002)(31966008)(80976001)(76482001)(56776001)(81686001)(62966002)(47446002)(77982001)(54316002)(84326002)(19580405001)(79102001)(19580395003)(69226001)(74662001)(50986001)(567704001)(74482001)(47736001)(59766001)(81816001)(50226001)(49866001)(47976001)(87936001)(74502001);DIR:OUT;SFP:;SCL:1;SRVR:AMXPR04MB247;H:DB3PRD0411HT001.eurprd04.prod.outlook.com;CLIP:;FPR:;RD:InfoNoRecords;A:1;MX:1;LANG:en; X-OriginatorOrg: franklynnevard.co.uk

Reporting-MTA: dns;AMXPR04MB247.eurprd04.prod.outlook.com Received-From-MTA: dns;DB3PRD0411HT001.eurprd04.prod.outlook.com Arrival-Date: Fri, 15 Nov 2013 08:54:25 +0000

Final-Recipient: rfc822;[email protected] Action: failed Status: 5.0.0 Diagnostic-Code: smtp;550 Authentication is required for relay Remote-MTA: dns;babcom-h2.lnc.net X-Display-Name: Pat Dobson

The question is, is this something that I can do something about (i.e. is it a configuration error on my users email settings) or do I need to go to the server hosts about it ? I have already contacted the server hosts and they say that it's nothing to do with them. What makes me suspicious is that most users have no problems.

1 Answer 1


If you look at your log report you can see that it is returning a 550 error related to Authentication issues. This is most likely due to the fact you have not checked My outgoing server (SMTP) requires authentication.

More information here:

When attempting to send email using Microsoft Outlook, Outlook Express, or other email client software, you may receive the message "550 Authentication is required for relay" from your mail server.

The reason for this error is that your email server is configured to require SMTP authentication to send outgoing mail, which is a way an email sender can be authorized. In order to resolve this issue you will need to configure your email client (Outlook, Outlook Express, Eudora, Thunderbird, etc) to send the appropriate credentials.

  • Thanks for this. I have notified a client who's having issues, let's hope that he can get it sorted . . .
    – Pat Dobson
    Nov 18, 2013 at 20:16
  • Well he hasn't come back to me to say it's still not working so this must have solved it . . .
    – Pat Dobson
    Nov 22, 2013 at 13:31

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