Windows Live Mail send error with Server Response: "550 5.1.1 Not our Customer"

With Windows Live Mail, some email messages are getting stuck in the Outbox, while others are sent but then some recipients report not receiving certain emails.  I don't know if the problems are related.

But I had a closer look at the first behavior, with two messages stuck in the Outbox.  Both had multiple addressees.  Both were replies created via Reply To All.  The send failed with the error: "The message could not be sent.  The setting for your outgoing email (SMTP) server might need to be configured.  To find the server settings for 'email address at comcastdotnet', please contact your email service provider."

Subject xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Server Error: 550
Server Response: 550 5.1.1 Not our Customer
Server: 'smtp.comcast.net'
Windows Live Mail Error ID: 0x800CCC79
Protocol: SMTP
Port: 465
(rest of the error not preserved)

The really interesting thing in my view is the part that says "To find the server settings for 'email address at comcastdotnet'."  But "email address at comcastdotnet" is not the user account, but instead is one of the addressees!!  So "Server Response: 550 5.1.1 Not our Customer" is not entirely surprising.  However, to add to the mystery, the correct user account and the erroneous user account reported in the error are both at-comcastdotnet.  I don't know if the erroneous user account (which is also one of the addressees) is a good, current address.   If not, then perhaps a bad address is one of the triggers of this behavior.

Many or most email messages are sent fine, so there does not seem to be a problem with the WLM account configuration.

There is this related post elsewhere: http://answers.microsoft.com/en-us/windowslive/forum/livemail-email/ive-got-error-550-message-repeatedly-showing-up-in/13da8517-9989-4866-8cec-53f67ae899d5.  The answer indicates either a problem with POP settings (seems irrelevant here), or a firewall blocking certain ports.  But if that were the case, wouldn't it block ALL outgoing email?
 

Question Info


Last updated September 13, 2019 Views 6,467 Applies to:

The problem is with one of the addresses you're trying to send to (0x800CCC79 means SMTP_REJECTED_RECIPIENT). There must have been an @comcast.net address in the addressee list that the Comcast server didn't recognize.

 

 

Noel Burgess | Certified Pedant | Claims to know a bit about Windows Live Mail

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Thanks, that is of interest.

But that leaves or gives rise to two questions.

1) Of greater concern: If one address in a multiple-addressees list is bad, does Windows Live Mail leave the message in the Outbox and refuse to send to the other addressees in the list?  (These two messages were stuck in the Outbox.)

2) Does WLM produce a misleading error message if the real problem was SMTP_REJECTED_RECIPIENT?
       I say this because the error message was "The message could not be sent.  The setting for your outgoing email (SMTP) server might need to be configured.  To find the server settings for 'email address at comcastdotnet', please contact your email service provider."
       The message seems to indicate a problem with my SMTP server setup, so I would expect it to cite my email address in connection with that, but instead it cites the email address of an addressee.

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Hi,

I simulate your issue in by end, and come up with this resolution.

1. No, If one address in your multiple-addresses list is bad or mistyped which is common error it will not save in your Outbox, it will go to your Drafts folder and you will also received Delivery Status Notification.

2.  For a possible workaround of the issue, please reconfigure your account by following the steps provided in this link.

Let us know the result.

Thanks

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I simulate your issue in by end, and come up with this resolution.

1. No, If one address in your multiple-addresses list is bad or mistyped which is common error it will not save in your Outbox, it will go to your Drafts folder and you will also received Delivery Status Notification.

2.  For a possible workaround of the issue, please reconfigure your account by following the steps provided in this link.

1. It seems that in this experiment, a bad address was entered in a list of otherwise good addresses, but the results do not duplicate the result here on either count.  Here, the emails stuck in the Outbox rather than going to the Drafts folder.  And there was no Delivery Status Notification -- the error was displayed in a popup, and there was the exclamation icon in a yellow triangle on the right side of the main window status bar.

2. That link is just the basic instruction on setting up an account.  The account settings here work *most* of the time, and I double-checked them. 

But to round out the problem description, I confirm that the address cited in the error message is a bad address.  (In the original description I said that I didn't know if it was a good, current address.)

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It looks like there is a bug here.  (And though MS is not accepting bug reports for this product, I did send this to their feedback/suggestions box for Live Mail.)

I created a new mail with multiple addressees, inserting the one known-bad address, and hit Send.

WLM responded by not sending the mail at all, but leaving it in the Outbox.  It also responded with the inaccurate and misleading error message indicating that the SMTP server settings are wrong:

The message could not be sent.  The setting for your outgoing email (SMTP) server might need to be configured.  To find the server settings for '<bad-addressee>', please contact your email service provider.

Subject xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Server Error: 550
Server Response: 550 5.1.1 Not our Customer
Server: 'smtp.comcast.net'
Windows Live Mail Error ID: 0x800CCC79
Protocol: SMTP
Port: 465
Secure (SSL): Yes

What WLM should have done is send the mail to all the addresses, move the message to the Sent folder, and rely on the bad address's domain owner (Comcast.net in this case) to bounce back a Failure Notice or Delivery Status Notification email.

WLM's behavior here is very difficult for average users to understand or remedy.  The work-around is to move the message from the Outbox to the Drafts folder, open it, remove the bad address, and re-send.

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If one address in your multiple-addresses list is bad or mistyped which is common error it will not save in your Outbox, it will go to your Drafts folder


When you click Send in a message compose window, the message is moved to the outbox to be sent at the next opportunity. It will not be saved to Drafts unless you issue a command to do so.

  • If the send fails, the message will remain in the outbox.
  • If the message is accepted by the mail submission server for onward transmission, it will no longer be in the outbox and may be moved to the Sent items folder.

and you will also received Delivery Status Notification.


That will only happen if the message has made it as far as a mail server that returns a DSN. In John's case, he was submitting a message to his ISP's server, which was able to check the address on the same domain before passing it on. This is why the server returned an error rather than having to wait for another server further down the line to report back. 

To test a scenario like this, you must (a) be connected to the Internet via the same ISP as in the original scenario, (b) submit to the same SMTP server and (c) address the message to a user on the same domain. I doubt you were in a position to conduct such a test.


Noel Burgess | Certified Pedant | Claims to know a bit about Windows Live Mail

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WLM responded … with the inaccurate and misleading error message indicating that the SMTP server settings are wrong:

I agree that this is not necessarily the most helpful error description. However, you should bear in mind that WLMail is trying to be helpful. The error returned by the server means that a recipient's address was rejected. WLMail then interprets this as best it can, and presents an error description that covers the most likely reason for the error, of potentially many different reasons. It doesn't say that your settings are wrong, just that they might be

It was common that mail servers would not allow relaying to other networks (ISPs) unless particular SMTP settings were applied. While a Comcast user could happily send messages to other Comcast users, they had to apply different settings to be able to send - relay - messages outside of Comcast's network. Any attempt to do so with the standard settings would result in the 'recipient rejected' error, so WLMail gives the error description you see. It's just unfortunate that in this particular case, the recipient's address was rejected for another reason - it didn't exist in Comcast's database. WLMail couldn't have known this.

If you're interested, there's a description of the pitfalls of relaying on this page: Troubleshoot 550, 553, and relay-prohibited errors
Noel Burgess | Certified Pedant | Claims to know a bit about Windows Live Mail

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I read the interesting article about relay errors.  Thanks.  (That was also an incisive analysis in the reply above the previous reply.)

And I appreciate it that a most-likely-explanation was presented by WLM.  However, it presented it with too little indication that there are other common causes for the error (here, an obsolete or mis-entered address).

I think words like these would have been better: "The message could not be sent.  Your outgoing email server rejected a recipient address.  One cause for rejection is incorrect or obsolete server settings.  Contact your email service provider to verify those settings."

Not only that, but because this message was created with Reply To All, and the error message cited, not my address as expected for an SMTP-misconfigured sort of message, but a bad address which I did not recognize, it looked at first like WLM had been hijacked and was being used to send some messages on behalf of bad-addressee.  A bit scary until the mist cleared.

Apart from that, there is the behavior in which it did not send the message to the good addresses but simply left the message in the Outbox.  It's very easy not to notice that a message is still in the Outbox.  I don't recall encountering that with other email clients.  I expect that the message would be sent to the good addresses.  If WLM wants not to send the message to the same-network-as-me bad-address such that I don't get a Failure Notice or Delivery Status Notification email bouncing back to me as expected, I don't object too much.  But at least send the message to the good addresses.

I notice that you did not address this behavior in your reply, so perhaps we agree on that point.

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I think words like these would have been better:


I'm sure the wording could be improved upon to cover all eventualities. Error messages, whether generated by the server or inserted by WLMail, will rarely be more than a guide. A different server might well have returned an entirely different error code for the same error. And you can guarantee that if someone were to re-code WLMail to produce more friendly messages, someone else would re-code a server to return a different error code for a particular error state.

it did not send the message to the good addresses but simply left the message in the Outbox. 


That again is, I think, up to the server. It could well have delivered messages to the good addresses and only returned an error for the bad ones - but it didn't. It rejected the message in its entirety, and WLMail has no other option than to retain the message in the outbox in case things improve. It does deliver a  warning sign in the status bar to alert you to the fact that something went wrong.

You might be interested in this list: Error codes 

 


 

Noel Burgess | Certified Pedant | Claims to know a bit about Windows Live Mail

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Your points about the lack of standards for error codes are well taken.

Thanks for the error codes list.  I did a search for such a thing and couldn't find one (though I restricted the search to microsoft.com).

Your statement about the good addresses not being sent the message due to a server decision (rather than WLM design) surprises me.  I cooked up a similar test message in Thunderbird (a bunch of good addresses, one bad one), and it sent to all the good addresses rather than keeping the message in the Outbox.  I got a bounce-back message about the bad address.  That is what I would expect.

However, I did that test at work, so not only was I using a different mail client, but a different ISP and a non-Comcast mail server.  Your nuanced knowledge may explain both behaviors.

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