E-Mail issue - Undelivered Mail Returned to Sender

The past few weeks I’ve started to have this issue on some of my outgoing mail not getting through. The strange part is that it all seems to happen with one domain ‘shaw.ca’ (my ISP). I am not using my ISP as the outgoing server & the same error has happened while sending mail with my treo.

The errors are as follows:

This is the Postfix program at host kungfu.dreamhost.com.

I’m sorry to have to inform you that the message returned below could not be delivered to one or more destinations.

For further assistance, please send mail to

If you do so, please include this problem report. You can delete your own text from the message returned below.

The Postfix program

******@shaw.ca: Name service error for shaw.ca: Host not found, try again


This report relates to a message you sent with the following header fields:

Message-id: 3199783111.8804538@www.chatteremail.com
Date: Tue, 24 May 2005 12:38:00 -0600
From: Dustin - My Company myemail@saskoncall.com
To: *****@thewebstation.ca, ********@shaw.ca
Subject: *********

Your message cannot be delivered to the following recipients:

Recipient address: *********@shaw.ca
Reason: Remote SMTP server has rejected address
Diagnostic code: smtp;550 5.1.1 unknown or illegal alias: ********@shaw.ca
Remote system: dns; (TCP||63914||11025) (pd4mr1so.prod.shaw.ca – Server ESMTP [Sun ONE Messaging Server 6.0 HotFix 1.01 [built Mar 15 2004]])

The issues seem to only happen with emails coming from my dreamhost email accounts, none of my other email accounts are affected.

Any ideas?


Diagnostic code: smtp;550 5.1.1 unknown or illegal alias: ********@shaw.caThis means the machine handling e-mail for shaw.ca doesn’t like the e-mail address. Besides the reasons stated in the diagnostic code, it could also be a problem with a spam filter they might be using; those things can be picky about who is sending the message.

:cool: Perl / MySQL / HTML+CSS

I’m starting to think that shaw isn’t the culprit… I received this one yesterday:

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

Subject: Logo
Sent: 5/24/2005 3:43 PM

The following recipient(s) could not be reached:

‘Boom Music’ on 5/24/2005 3:43 PM
554 **********@boommusic.com: Relay access denied

Shaw (ISP) also believes that it’s the dreamhost (Remote SMTP) server… what gives?


Are the messages being sent from the machine hosting your site, eg a CGI script or webmail, or if you are using a client, what client (Outlook, Thunderbird, etc)?

  1. Make sure you are using authentication for your SMTP settings
  2. Trying switching the SMTP port from 25 to 587

“Relay access denied” is usually because you aren’t authenticating. When your client goes to send a message, it connects to your SMTP server and sets up an “envelope”, in which it specifies which address is sending the message and who it is being sent to. In order to prevent people from using an SMTP server without authorization, the outgoing server will also require a username and password. Otherwise if the SMTP server doesn’t know who it is talking to, it is considered a “relay”.

See E-mail Configuration

:cool: Perl / MySQL / HTML+CSS

It’s actually with 2 different clients (Outlook for Windows, ChatterEmail for PalmOS), both are using authentication. I have been using 587 as my port in Outlook.

I’ll review my settings in both applications to see if I can track down the source.

I appreciate the help. Hopefully I can get it resolved soon.