About email bounceback error messages

Products

• Email Security.cloud

Issue/Introduction

The error messages in the code boxes are examples of email bounce backs.  The exact error and message might vary depending on your operating system.

Resolution

 

Message filtered - 553-Message filtered: This error message indicates that your email was blocked as spam by our Signaturing antispam filter.

<[email protected]>: host cluster6.us.messagelabs.com[216.82.249.99]

said:

   553-Message filtered. Please see the FAQs section on spam 553-at

   http://www.messagelabs.com/support/ for more 553 information.

(#5.7.1) (in

   reply to end of DATA command)

 

 Try the following steps to resolve the issue:

1.            Check if your sending IP is on any black lists. You can check this is http://www.dnsstuff.com. Here you can see any third party lists that may have received spam from your mail server. If your IP address is on any block lists, request to have your IP address removed, wait 24 hours, and then try to resend your email.

2.            Ensure your mail server is not an open relay - http://www.abuse.net/relay.html.

3.            If your internet line is provided by DSL or cable that shares IPs with residential users, ensure that your mail server sends to your ISP’s smart host instead of directly to the internet. This reduces the potential of your email being detected in error as coming from a Trojan infected home user machine.

4.            Ensure the email that you are sending does not contain any spam content (i.e. forwarded spam or ‘spamvertised’ URL’s).

5.            Ensure that your mail server is configured correctly.

6.            Ensure you have no virus infected machines on your network that are being used to send spam through your mail server.

7.            Ensure you have no exploitable web scripts on your web servers that could be abused to send spam. The most commonly used one is PHP contact scripts, which spammers can easily abuse the PHP “mail()” function to send what they want.

8.            Make sure any opt-in newsletters contain an opt-out link to be certain users can easily unsubscribe. If the problem persists, contact the recipient by other means (e.g. fax or phone) and request that your email address be added to their approved senders list through the Symantec.cloud portal.

 

User unknown - This error message indicates that the address you sent the email to does not work, either because it is inactive or the address is incorrect/nonexistent.

<[email protected]>:

1.1.1.1 does not like recipient.

Remote host said: 550 5.7.1

<[email protected]>... User unknown

 This message was created automatically by mail delivery software.

 A message that you have sent could not be delivered to one or more

 recipients. This is a permanent error. 

 

The following address failed:

 <[email protected]>: 550 5.1.1 User unknown

 

No mailbox here by that name - This error message indicates that the address you sent the email to does not work, either because it is inactive or the address is incorrect/nonexistent.

 Hi. This is the qmail-send program at archon.xter.net.

 I'm afraid I wasn't able to deliver your message to the following addresses.

 This is a permanent error; I've given up. Sorry it didn't work out.

 

 <[email protected]>:

 Sorry, no mailbox here by that name. (#5.1.1)