550-The recipient cannot be verified email problem

Seems to be a simple problem, but I can not figure this one out:

I have a Ubuntu server setup using the perfect setup for 6.06 and with Ispconfig. This server's hostname is server.anaselectronics.com.

anaselectronics.com is on the main IP of the system. On a 2nd IP, I have asuslaptops.net. Both of these sites are setup through Ispconfig. I can send and receive emails to both domains successfully from:
- from email address of one domain to the other domain
- from php scripts on the server using the php mail() function
- from my gmail account

The problem I have occurs when sending email from a different server housed at a different datacenter. The hostname is server.nyxmotorsports.com and the domain being used for sending the email is case-mod.com.

When sending email from [email protected] to [email protected], the emails go through just fine.

When sending email from [email protected] to [email protected], I get the following errors:

If sending from thunderbird, it says

If sending mail from telnet mail.case-mod.com 25, it accepts RCPT TO: <[email protected]>, but RCPT TO:<[email protected]> returns

If sending from the php mail() function using a php script on case-mod.com server, emails sent to [email protected] go through. Any emails sent to [email protected] do not come through and bounce back after few hours:

So basically, it seems the site setup on the main IP of the server can receive emails without any problems. The problem I am having here seems to occur on a domain that is setup on a secondary IP in Ispconfig.

Thanks in advance for any help.

 

var/log/mail.log shows the following just after trying to send an email to [email protected] from thunderbird:

Another question: currently the MX records for asuslaptops.net points to it's IP address. Should these point to anaselectronics.com instead?

What should be in /etc/mailname...I currently have "www.anaselectronics.com"

 

another question

Do you I need to list additional IP's in /etc/hosts. Currently I have:

Code:

127.0.0.1       localhost.localdomain localhost
8.14.145.114    server.anaselectronics.com server

Do I need to add 8.14.145.115 asuslaptops.net asuslaptops?

 

The main IP of the server is 8.14.146.114. I have a 2nd IP of 8.14.146.115.

In Ispconfig, anaselectronics.com has IP set to 8.14.145.114 and asuslaptops.net is set to 8.14.146.115

In DNS, which is set through my registrar, the A and MX records for asuslaptops.net both point to 8.14.146.115.

So you are saying that the A record should point to 8.14.146.115 and the MX record point to 8.14.146.114?

 

Ok...I have changed the MX record for asuslaptops.net. It doesn't solve my problem of the emails being rejected when emailed from case-mod.com.

As i mentioned, sending from gmail works just right. What I think it happening is that my postfix is rejecting email from case-mod.com perhaps due to some setting it doesn't like for email received from case-mod.com . Any way to find out why this is happening?

 

Thanks for the direction, Till.

After more reading, I saw some mention of /etc/localdomains file. It seems on case-mod.com server, it showed asuslaptops.net as a localdomain. Deleting that entry from cpanel seems to have fixed the issue.

You were correct that it was a problem on that server.