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I'm posting this because google and microsoft search turned up empty.
We have an exchange server for our email set up, however it is reporting 5.1.1 errors for email adresses that we KNOW to be valid...this ofcourse bother us a lot, but we cannot find a culprit for it.
Has anybody had similar issues or does anybody know what direction to search in, if you need more information please ask, i am unsure what i should provide you with in this case.
Hey Hey,
Are you using real time block lists?? I found this on an MS Support site
Some things you may want to include to assist with troubleshooting...Quote:
Source: http://support.microsoft.com/default...b;en-us;823866
SMTP command:
RCPT TO: [email protected]
Mail flow process that occurs:
1. Exchange Server checks the SMTP addresses in the exceptions list to the block list service rules. To view this list, click Exceptions on the Connection Filtering tab of the Message Delivery Properties dialog box. If the sender's SMTP address appears in this list, Exchange Server bypasses the RBL.
2. Exchange Server checks the recipients that appear in the Recipients list on the Recipient Filtering tab of the Message Delivery Properties dialog box. If the message recipient appears in this list, Exchange Server returns the following error message to the sender:
550 5.7.1 Requested action not taken: mailbox not available
3. Exchange Server checks the RBL. If the sender is from a blocked domain, Exchange Server closes the connection, and then returns the following error message to the sender:
550 5.7.1 169.254.1.253 has been blocked by default.
4. Exchange Server determines whether the Filter recipients who are not in the Directory check box is selected on the Recipient Filtering tab of the Message Delivery Properties dialog box. If this check box is selected, and if the recipient does not appear in the Active Directory directory service, Exchange Server returns the following error message to the sender:
550 5.1.1 User unknown
In this scenario, Exchange Server does not close the connection, and the sender can continue to try to deliver mail to other e-mail addresses.
1. Which version of Exchange is this... When was it last updated (i.e. is it fully up to date)
2. Are you sending to internal users or external users (@yourdomain.com or @otherdomain.com)
3. Your server is reporting this when internal email is sent, external email or both?
4. These known valid email addresses... are they new... (Did the users or the problem come first)
Peace,
HT
We are not using them as far as i am aware.
1. exchange 2003 6.5.7638.1 SP2, windows 2003 server enterprise
2. External users, for instance [email protected] but the errors are not confined to this domain I can for instance send mail to my gmail account fine. We checked at the local newspaper and they are not blocking us in any way and can send mail to us without problems.
3. Only externaly
4. This problem has been around for a decent amount of time I am an intern to a new sysadmin here (before the sysadmin was hired someone else used to to the IT part time with his normal functions) and the problem was around since he came here, however there was(still is) a decent backlog of problems around.
Hey Hey,
So just to clarify.
If you send an email, [email protected] to an address at the local newspaper, [email protected], the localnewspaper.nl SMTP server will respond with the 5.1.1 User Unknown problem??
That's how I read the 4 answers you gave... and if that's the case I'd say it's a problem on their end... Maybe you've somehow made it onto one of the public blacklists and a few companies in the area are using it???
Peace,
HT
We have been down that raod already, we are as far as we know not on any blacklists (that we can find) and according to them we are also not on some kind of blacklist from them.
Acording to the sysadmin it is OUR server creating these mesages.
Translating out of dutch:
Subjects: test
Sent: 29-3-2006
the following adresses were unreachable
[email protected] on 29-3-2006 9:28
The organisation you sent this message to reports that the mail account does not exist. Check the account or contact the account holder.
Our message did not reach all recipeints
<mailserver.domain.local #5.1.1 smtp;550 5.1.1 <[email protected]>... No such user>
---
We have similar messages for various domains. about 2 or 3 per day.
The error is coming from thier end...so its not your server.
You may want to verify the email address...like try to send from a hotmail\yahoo account and see if it returns.
Also...how are you sending your mail...I have had some problems if our mailserver does not have a valid return dns...so you may have to upload to ISP for mail to get accepted from some domains.
MLF
I can send and receive mail from that adress on my gmail.
I dont want to sound like an idiot here, but could you explain what you mean by return dns ?
I have to admit that i know very little about mail servers of any kind, but am willing to learn.
Well...if you are sending email from your server....via smtp...you may need a reverse lookup
resolving your IP address to mymailserver.mydomain.com
Have you contacted your ISP???
MLF