Postfix error:    Postfix SMTP server: errors from[]

Posted on 2011-02-10
Last Modified: 2012-08-13
I am getting the below email sent to me and need a little help understanding it:

Transcript of session follows.
 Out: 220 ESMTP Postfix
 In:  EHLO
 Out: 250-SIZE 10240000
 Out: 250-ETRN
 Out: 250-STARTTLS
 Out: 250-8BITMIME
 Out: 250 DSN
 Out: 454 4.3.0 TLS not available due to local problem
 In:  MAIL FROM:<> SIZE=4963
 Out: 250 2.1.0 Ok
 In:  RCPT TO:<>
 Out: 550 5.1.1 <>: Recipient address rejected:
     User unknown in virtual alias table
 In:  DATA
 Out: 554 5.5.1 Error: no valid recipients
 In:  QUIT
 Out: 221 2.0.0 Bye

1-If I am looking at it right it is just telling me as an administrator that this message was dropped due to user not known.
2-how can i stop this message from coming to me if it is just a informational message?
3-how do i verify that it is not delivering a NDR if it is?

server is Centos
MTA Postfix
Question by:knightdogs
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
LVL 26

Expert Comment

ID: 34865489
Is this your server or some hosting server somewhere?

Yes, this is just an NDR. Based on the sender ( it looks like a phishing email. isn't a valid domain so there is no place to bounce the mail to, so it gets sent to the admin. This is how it is supposed to work. Perhaps you should set up a special mailbox just for NDRs that are undeliverable so you stop getting them.
LVL 26

Expert Comment

ID: 34865494
actually it is a valid domain (I fat-fingered it when doing the lookup), but still, it's probably forged.

Author Comment

ID: 34865541
This is my server, not a hosted server.  In exchange you can turn off NDR's i dont see how to turn them off in postfix, am i missing something?
LVL 19

Accepted Solution

bevhost earned 500 total points
ID: 34867954
I don't think it's an NDR, as if it were, the sender address would be <>.
It's also not coming from an RFC compliant MTA, becuase it still attempts the DATA command even after it has not got any valid recipients.
I think it is some sort of spam agent.

Author Closing Comment

ID: 34871740
Thank you for your help with this.

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Phishing attempts can come in all forms, shapes and sizes. No matter how familiar you think you are with them, always remember to take extra precaution when opening an email with attachments or links.
Sometimes clients can lose connectivity with the Lotus Notes Domino Server, but there's not always an obvious answer as to why it happens.   Read this article to follow one of the first experiences I had with Lotus Notes on a client's machine, my…
In this video we show how to create a Resource Mailbox in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.: Navigate to the Recipients >> Resources tab.: "Recipients" is our default selection …
To show how to generate a certificate request in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.:  First we need to log into the Exchange Admin Center. Navigate to the Servers >> Certificates…

729 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question