Topic: 550 5.1.1 USER UNKNOWN

[dilligaf]

sme server 7.4
A few users complain that people that used to be able to e-mail them can't.

I requested one of the returned messages as follows:

+++++++++++++++++
From:   System Administrator
Sent:   Thursday, April 30, 2009 3:53 PM
To:     Judy Borgerson
Cc:     'kevin@theirdomain.com'
Subject:        Undeliverable: email

Your message did not reach some or all of the intended recipients.

Subject:  FW: email
Sent:     4/30/2009 3:53 PM

The following recipient(s) could not be reached:

'kevin@theirdomain.com' on 4/30/2009 3:53 PM
550 5.1.1 <kevin@theirdomain.com>... User unknown
+++++++++++++++++

But he (they exist)
Any idea what we can do to solve the problem?

[CharlieBrady]

'kevin@theirdomain.com' on 4/30/2009 3:53 PM
550 5.1.1 <kevin@theirdomain.com>... User unknown
+++++++++++++++++

'User unknown' is not an SME server message. The sender's mail server attempted to deliver that message to a non-SME server, which didn't accept it.

Check your DNS. If you have a backup MX server for your domain, remove it.

[dilligaf]

this issue continues on for us, with more and more vendors unable to e-mail us.
I contacted easydns about removing the backup mx, this was their response:

you could always remove "smtp2.easydns.com" from your MX records within the DNS settings
for your domain name, yet if your mailserver goes offline, you would not have the added benefit of a backup mailspooling server
for your domain's email.

thanks in advance for any further help.

[mike_mattos]

this typically happens when ISP's increase their security.  You may be able to send to Bell but not Rogers.  We lost the ability to email FIDO but could email ROGERS , the parent company of fido!

Solution was to tell SME to relay all email via my ISP (server manager - email -change email delivery settings-Address of Internet provider's mail server )

It will always slow your mail down a wee bit, and when your ISP has email problems, a lot, but it will resolve a lot of security issues

[CharlieBrady]

Solution was to tell SME to relay all email via my ISP (server manager - email -change email delivery settings-Address of Internet provider's mail server )

dilligaf is not reporting a problem with being unable to send mail. He's reporting a problem of outside users not being able to send mail to his server.

dilligaf's problem has nothing to do with SME server. It is some misconfiguration outside of SME server. Because he hasn't shown the real domain name, and hasn't shown the IP address of the server which generated the bounce message, nobody else can help him to investigate the root cause.

[mike_mattos]

oops!  the some work some don't is usually outgoing, got confused by the substitution of names!

If you are using easydns, you should be careful that you don't add mail.mydomain.com and neglect to update it !

Better to wildcard *.mydomain.com as an alias or just use mydomain.com as the mailserver

Also,  the backup mail service at Easydns seems to work if your server is off line, unless you have a wrong IP for your domain, and a server with that wrong IP sends out error messages and the backup server does not get the mail!

EasyDNS tech support are pretty friendly, they explained it to me when I was having ISP issues, so I would manually set them up when I was reconfiguring systems ratehr than trust the automatic feature.

 

[dilligaf]

Charlie,
wildrowspump.com is server not recieving (142.179.184.208)
ecm.ab.ca (216.251.43.14) is one domain, the other is astecsafety.com 216.251.32.98

[janet]

dilligaf

Might be related to DNS configuration for your domain, see PTR & SPF sections at

http://wiki.contribs.org/SME_Server:Documentation:Administration_Manual:Appendix

[CharlieBrady]

Charlie,
wildrowspump.com is server not recieving (142.179.184.208)
ecm.ab.ca (216.251.43.14) is one domain, the other is astecsafety.com 216.251.32.98

What's need to debug is the recipient email address which was rejected, and the server IP which rejected the email.

My guess from what you have told us is kevin@wildrowspump.com and 64.68.200.53.

According to Google, the most likely mail server to have generated that rejection message is Microsoft Exchange. Perhaps that will help you work out where the error has occurred.

The actual bounce message (including the headers you don't usually see) should contain sufficient information to work out exactly where the message had got to when it was determined to be undeliverable.

[dilligaf]

this is crazy, yet another one, the owner and me are very frustrated, these users exist:

> The message could not be sent because one of the recipients was rejected =
> by the server. The rejected e-mail address was =
> 'alyson@wildrowspump.com'. Subject 'FSR Proof', Account: =
> 'mail.imagepress.ca', Server: 'smtp.imagepress.ca', Protocol: SMTP, =
> Server Response: '550 5.1.1 <alyson@wildrowspump.com>... User unknown', =
> Port: 25, Secure(SSL): No, Server Error: 550, Error Number: 0x800CCC79

[CharlieBrady]

this is crazy, yet another one, the owner and me are very frustrated, these users exist:

> The message could not be sent because one of the recipients was rejected =
> by the server. The rejected e-mail address was =
> 'alyson@wildrowspump.com'. Subject 'FSR Proof', Account: =
> 'mail.imagepress.ca', Server: 'smtp.imagepress.ca', Protocol: SMTP, =
> Server Response: '550 5.1.1 <alyson@wildrowspump.com>... User unknown', =
> Port: 25, Secure(SSL): No, Server Error: 550, Error Number: 0x800CCC79

"Error Number: 0x800CCC79" according to google is what Outlook Express will tell you when relaying is denied:

http://blog.connectto.net/index.php?blog=8&title=outlook_express_error_number_0x800ccc79&more=1&c=1&tb=1&pb=1

Whoever is attempting to use the smtp.imagepress.ca mail server does not have permission to relay mail via that server. Perhaps they need to authenticate, or be physically located on a local network adjacent to that server. They should consult their technical support, in any case.

It has nothing to do with wildrowspump.com. Or with SME server.

[dilligaf]

the server log is full of these entries, are they related?

May 28 11:15:06 wrpcsrvr smbd[13323]: [2009/05/28 11:15:06, 0] lib/util_sock.c:get_peer_addr(1224)
May 28 11:15:06 wrpcsrvr smbd[13323]:   getpeername failed. Error was Transport endpoint is not connected
May 28 11:15:06 wrpcsrvr smbd[13323]:   Connection denied from 0.0.0.0
May 28 11:15:06 wrpcsrvr smbd[13323]: [2009/05/28 11:15:06, 0] lib/util_sock.c:write_data(562)
May 28 11:15:06 wrpcsrvr smbd[13323]:   write_data: write failure in writing to client 0.0.0.0. Error Connection reset by peer
May 28 11:15:06 wrpcsrvr smbd[13323]: [2009/05/28 11:15:06, 0] lib/util_sock.c:send_smb(761)
May 28 11:15:06 wrpcsrvr smbd[13323]:   Error writing 5 bytes to client. -1. (Connection reset by peer)
May 28 11:21:07 wrpcsrvr smbd[4343]: [2009/05/28 11:21:07, 0] lib/util_sock.c:get_peer_addr(1224)
May 28 11:21:07 wrpcsrvr smbd[4343]:   getpeername failed. Error was Transport endpoint is not connected
May 28 11:21:07 wrpcsrvr smbd[13787]: [2009/05/28 11:21:07, 0] lib/util_sock.c:get_peer_addr(1224)
May 28 11:21:07 wrpcsrvr smbd[13787]:   getpeername failed. Error was Transport endpoint is not connected

[dilligaf]

oops!  the some work some don't is usually outgoing, got confused by the substitution of names!

If you are using easydns, you should be careful that you don't add mail.mydomain.com and neglect to update it !

Better to wildcard *.mydomain.com as an alias or just use mydomain.com as the mailserver

Also,  the backup mail service at Easydns seems to work if your server is off line, unless you have a wrong IP for your domain, and a server with that wrong IP sends out error messages and the backup server does not get the mail!

EasyDNS tech support are pretty friendly, they explained it to me when I was having ISP issues, so I would manually set them up when I was reconfiguring systems ratehr than trust the automatic feature.

 

I went to easydns,
under mx settings I have mail for zone wildrowspump.com is handled by servers mail.wildrowspump.com.
mail.wildrowspump.com is pingable, and you can telnet to the mailserver.

Then under hosts I deleted what was there and put *.wildrowspump.com / 142.179.184.208

Now If I try and ping wildrowspump.com, I get no response, which I should with the wildcard?
I can ping mail.wildrowspump.com

[CharlieBrady]

the server log is full of these entries, are they related?

How could they be? The problem you have described has nothing to do with SME server.

Is that not clear yet?

[CharlieBrady]

I went to easydns,

Go back there again, and put things back to how they were before.

[mike_mattos]

in hosts I have two entries, mydomain.com and *.mydomain.com
in aliases I point www.mydomain.com to mydomain.com

mail for domain  mydomain.com is handled by server  mydomain.com  5   and smtp2.easydns.com 10

I update both with dynsite, it and probably other update programs share  a VPN problem.

Be VERY careful if you use VPN on the dynsite computer, I've seen dynsite update easydns with the IP the VPN connection made while I was doing a support call, and guess what?  No one could email my server!  Very hard to find, because dynsite of course repaired the address when I closed the VPN connection!  The remote VPN site has an email server, and my mail was being directed there!

[dilligaf]

How could they be? The problem you have described has nothing to do with SME server.

Is that not clear yet?

Charlie, I understand your lack of patience, and apologize,
but the vendors that are unable to e-mail us, are not willing to fo anything on their end, they can e-mail all their other clients.
I am trying to be a PITA, I just don't have the expertise to figure out the problem,that's why I am here.

[dilligaf]

in hosts I have two entries, mydomain.com and *.mydomain.com
in aliases I point www.mydomain.com to mydomain.com

mail for domain  mydomain.com is handled by server  mydomain.com  5   and smtp2.easydns.com 10

I update both with dynsite, probably other update programs have a VPN problem.

Be VERY careful if you use VPN on the dynsite computer, I've seen dynsite update easydns with the IP the VPN connection made while I was doing a support call, and guess what?  No one could email my server!  Very hard to find, because dynsite of course repaired the address when I closed the VPN connection!  The remote VPN site has an email server, and my mail was being directed there!

what is the dynsite computer?

[janet]

dilligaf

I just don't have the expertise to figure out the problem,that's why I am here.

So start absorbing what Charlie is saying, he is an extremely experienced person and is being very patient. The problem is your unwillingness to accept his answer.

Get the original sender to forward to you a "complete" returned message. It must be sent to you by Forwarding as an attachment, rather than just forwarding.
You need to get all the Header information to see the path the message has taken, and then you will see the server name & IP etc that is rejecting the message.
In your email client look at the Header or Source or Properties information for the original returned email.

[dilligaf]

will do, and I know about Charlie's capacity/ability,
thank you.

[mike_mattos]

If you have a dynamic name service, you have some way of notifying them when your IP address changes.

Dynsite is a program that does this automatically, on a windows computer.  Historically, SME server would update you PRIMARY domain address OK, but would not update your virtual domains.  Dynsite allows you to have a list of domains updated automatically.

[dilligaf]

gotcha, we're static.

[mike_mattos]

This just reminded me of a similar failure caused by  a clients ISP.  <bell.ca>
 
Client had his own server hosted offsite.  ISP <bell.ca> charged client for a hosting package he was not using, and set up a service under client's domain name.  Ignorant client told ignorant bell rep he wanted his email address to be his domain address, rep turned on hosting service for that domain name on a bell.ca server. 

Client could receive email from most of the world EXCEPT from bell.ca customers (people for whom bell.ca was the ISP) , because bell.ca customers were routed to the bell.ca hosting service, NOT to the customer's server.

took a while to figure it out

[dilligaf]

Mike,
A phone call to telus (ISP) looks like similar issue (they say they found something)
will report back full details when working again.
thanks