Error 551: This mail server requires authentication

Discussion regarding the Standard version.
avionwbt
Posts: 10
Joined: Sun Mar 18, 2012 3:48 am

Error 551: This mail server requires authentication

Post by avionwbt » Sun Mar 18, 2012 4:35 am

This one has me beat. I've read the documentation :shock: and think I understand it :) but email generated by a classic ASP/ASP.NET application fails with a 551 error.
MailEnable Standard version 6.03 under IIS7 & Windows Server 2008 64-bit Web edition.

What has been tried is the Relay settings under SMTP properties, with:
  • Allow relay for authenticated senders enabled and disabled (when enabled, using a specially added Windows account with User and IIS_IUSRS rights)
  • Allow relay for privileged IP addresses (with 2 server IP addresses and 127.0.0.1)
  • Allow relay for local send addresses (enabled)
  • POP before SMPT authentication (enabled and disabled)
In addition, under the SMTP Security tab, all the protection settings have been cleared.
If nothing else, this mail server should at least be a gift for spammers.

The result is consistent, returning a 551 error:
Web application log:
SendMail: error calling SendMail method in object "wbtmanemail.mailsender"
To:ian@avionwbt.co.uk
From:support@avionwbt.co.uk
Subject:Course Expiration.
The server rejected the sender address. The server response was: 551 This mail server requires authentication before sending mail from a locally hosted domain. Please reconfigure your mail client to authenticate before sending mail.

SMTP-Activity-DTG log:
03/18/12 03:30:54 SMTP-IN 70DEB15C124D46AE9DB2465BE2BD758A.MAI 692 ::1 MAIL MAIL FROM: <support@avionwbt.co.uk> 551 This mail server requires authentication before sending mail from a locally hosted domain. Please reconfigure your mail client to authenticate before sending mail. 169 37

ex-DTG log:
2012-03-18 03:30:54 ::1 SMTP-IN 684 MAIL MAIL+FROM:+<support@avionwbt.co.uk> 551+This+mail+server+requires+authentication+before+sending+mail+from+a+locally+hosted+domain.+Please+reconfigure+your+mail+client+to+authenticate+before+sending+mail. DSVR010649 169 37

The web application has no facility to "reconfigure your mail client to authenticate before sending mail" and I just have to get mailEnable to accept (send) automatically generated email - which I thought one of the SMTP Relay options would allow.

Am I missing something here? Are there additional permissions required somewhere?

MailEnable-Ian
Site Admin
Posts: 9397
Joined: Mon Mar 22, 2004 4:44 am
Location: Melbourne, Victoria, Australia

Re: Error 551: This mail server requires authentication

Post by MailEnable-Ian » Tue Mar 20, 2012 4:28 am

Hi,

Navigate within the SMTP properties to the "security" tab. Under the "Address spoofing" section set the option to "privileged IP's can impersonate". Ensure that the IP address of where the form resides on has been added to the SMTP privileged IP's can relay list.
Regards,

Ian Margarone
MailEnable Support

avionwbt
Posts: 10
Joined: Sun Mar 18, 2012 3:48 am

Re: Error 551: This mail server requires authentication

Post by avionwbt » Tue Mar 20, 2012 5:41 am

Thank you for responding, Ian.

Both IP addresses plus 127.0.0.1 exist in the SMTP privileged IP's can relay list.

The options for Spoofin (prevention) on my system are:
*Anyone can spoof sender addresses
*Authenticated users can spoof sender addresses
*Authorized connections can spoof sender addresses.

Not sure which selection you meant (2nd or 3rd) - the setting was on the 2nd (Authenticated users...) so changed it to 3rd, but with the same 551 error.

Changed it to the 1st option (Anyone can spoof) and got a 503 error when generating a web application email (by running the schedule batch file):
The server rejected one or more recipient addresses. The server response was: 503 This mail server requires authentication when attempting to send to a non-local e-mail address. Please check your mail client settings or contact your administrator to verify that the domain or address is defined for this server.

Doe this help diagnosis?

MailEnable-Ian
Site Admin
Posts: 9397
Joined: Mon Mar 22, 2004 4:44 am
Location: Melbourne, Victoria, Australia

Re: Error 551: This mail server requires authentication

Post by MailEnable-Ian » Tue Mar 20, 2012 5:47 am

Hi,

OK, setting the first option means that authentication is not enforced when a local mailbox sends to another locally hosted mailbox, which would stop the 551 error. The new 503 error means that the form is not authenticating and declined relay rights. Are you sure the IP is part of the privileged IP's to relay list? Also under the "Advanced SMTP" tab within the inbound authentication section is the option set "do not require authentication"?
Regards,

Ian Margarone
MailEnable Support

avionwbt
Posts: 10
Joined: Sun Mar 18, 2012 3:48 am

Re: Error 551: This mail server requires authentication

Post by avionwbt » Tue Mar 20, 2012 6:27 am

The inbound authentication section within the "Advanced SMTP" tab is confirmed as set "do not require authentication".
I can remotely access the server on both the allowed IP addresses:
accessControl.gif
accessControl.gif (4.68 KiB) Viewed 47934 times

avionwbt
Posts: 10
Joined: Sun Mar 18, 2012 3:48 am

Re: Error 551: This mail server requires authentication

Post by avionwbt » Tue Mar 20, 2012 6:31 am

And also, with these settings I received my copies of the generated emails (my email uses this server), but 503 errors arose for external addressees. This is the first time I have received emails addressed to me.

avionwbt
Posts: 10
Joined: Sun Mar 18, 2012 3:48 am

Re: Error 551: This mail server requires authentication

Post by avionwbt » Tue Mar 20, 2012 6:51 am

... and now I can't send email, with the following Outlook error: 'None of the authentication methods supported by this client are supported by your server.'
and I haven't been able to fix this yet...

MailEnable-Ian
Site Admin
Posts: 9397
Joined: Mon Mar 22, 2004 4:44 am
Location: Melbourne, Victoria, Australia

Re: Error 551: This mail server requires authentication

Post by MailEnable-Ian » Wed Mar 21, 2012 5:41 am

Hi,

Have you specified a specific authentication type in the Outlook account settings?
Regards,

Ian Margarone
MailEnable Support

avionwbt
Posts: 10
Joined: Sun Mar 18, 2012 3:48 am

Re: Error 551: This mail server requires authentication

Post by avionwbt » Wed Mar 21, 2012 6:00 am

No - "Require logon using Secure Password Authentication (SPA)" is unchecked.
All inbound mail is downloaded OK.
I can send email through another mail server OK, using the same settings...

MailEnable-Ian
Site Admin
Posts: 9397
Joined: Mon Mar 22, 2004 4:44 am
Location: Melbourne, Victoria, Australia

Re: Error 551: This mail server requires authentication

Post by MailEnable-Ian » Thu Mar 22, 2012 12:33 am

Hi,

Private message me with server login details and Ill a take quick look at the configuration settings.
Regards,

Ian Margarone
MailEnable Support

avionwbt
Posts: 10
Joined: Sun Mar 18, 2012 3:48 am

Re: Error 551: This mail server requires authentication

Post by avionwbt » Tue Mar 27, 2012 1:26 am

All my problems and agonising in this thread have been resolved with the timely and helpful off-line support of Ian Margarone (MailEnable Support), and I want to say here that this support has been as good as it can get. :D
Thank you, Ian

neildt
Posts: 12
Joined: Wed Apr 23, 2014 9:26 pm

Re: Error 551: This mail server requires authentication

Post by neildt » Fri May 02, 2014 12:16 pm

Ian, I'm experiencing the exact same issue as per my post here http://forum.mailenable.com/viewtopic.php?f=2&t=27421 that you have responded to. I'm running Windows 2012, MailEnable version 8.04 Standard Edition.

Can you please advise the fix you provided avionwbt

MailEnable-Ian
Site Admin
Posts: 9397
Joined: Mon Mar 22, 2004 4:44 am
Location: Melbourne, Victoria, Australia

Re: Error 551: This mail server requires authentication

Post by MailEnable-Ian » Mon May 05, 2014 12:04 am

Hi,
Ian, I'm experiencing the exact same issue as per my post here http://forum.mailenable.com/viewtopic.php?f=2&t=27421 that you have responded to. I'm running Windows 2012, MailEnable version 8.04 Standard Edition.

Can you please advise the fix you provided avionwbt
In your other post you have described that your problem is that your firewall application is able to relay without authentication even though you have the option to enforce all inbound connections to authenticate. Lets work on your other post to make things easier.
Regards,

Ian Margarone
MailEnable Support

Charithsilva79
Posts: 1
Joined: Thu Mar 21, 2019 1:56 pm

Re: Error 551: This mail server requires authentication

Post by Charithsilva79 » Thu Mar 21, 2019 2:01 pm

Can you explain how this was sorted. I want to use the Authorised connections can sppo sender addresses and i have added relay server IP ranges but it still giving

Remote Server returned '<mail.xxxxx.co.uk #5.0.0 smtp; 551 This mail server requires authentication before sending mail from a locally hosted domain. Please reconfigure your mail client to authenticate before sending mail.>'

can anybody help

MailEnable-Ian
Site Admin
Posts: 9397
Joined: Mon Mar 22, 2004 4:44 am
Location: Melbourne, Victoria, Australia

Re: Error 551: This mail server requires authentication

Post by MailEnable-Ian » Tue Mar 26, 2019 4:16 am

Hi,

Have you checked the SMTP log files to ensure that incoming address is the one you added to the privileged IP's can relay list?
Regards,

Ian Margarone
MailEnable Support

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