postfix rejecting messages

Hi there, I am trying out virtualmin as a potential replacement for Plesk. I did an install using your install script on a clean install of Centos 5. The installation appeared to be successful with no error messages. I was able to set up a virtual server successfully. I then set up an email account When I try to send email to this account, my email client (Thunderbird) is able to connect to the Postfix server, then gets a message saying "The mail server responded: Recipient address rejected: User unknown in virtual mailbox table....."

I have logged into the server and inspected the virtual mailbox table and the email address is present. The maillog says "Sep 6 08:56:24 ezezpz postfix/local[6397]: fatal: open database /etc/aliases.db: No such file or directory" So it seems that Virtualmin has misconfigured Postfix.

Have other people reported this inconsistency? Is there a fix?

kind regards,

Mark Brown



Howdy -- I have two different suggestions on what to look for.

First, after logging in as root over SSH, try running the command "newaliases". If you don't have an aliases.db file, that command should generate it.

Second, run the command "hostname". Whatever name comes up after you run that, does that exist in both /etc/hosts, as well as on the "mydestination" line in /etc/postfix/

thanks for suggestions. Hostname exists in hosts and on mydestination line in

the file virtual.db exists and has my email address in it.

I can log in to usemin to send emails..

My password gets rejected when I try to send email through Thunderbird.

Any more ideas much appreciated!

Ah, so that sounds like a new problem, as originally I believe we were looking at an issue with emails getting rejected.

To figure out what's going awry connecting to Dovecot, take a look in /var/log/maillog after your password is rejected. What error(s) do you see there around the time it rejected your connection?

Also, what's the full error message that Thunderbird gives you?

both problems described in first post are still nowhere closer to resolution. May I ask how mature the product is? I was wanting to use it for professional webhosting for my customers, but I am a bit wary given that the mail server does not operate on a clean install of Centos 5.

Joe's picture
Submitted by Joe on Wed, 09/08/2010 - 17:11 Pro Licensee

May I ask how mature the product is?

You may, though you may find it more enlightening to google about it. Virtualmin is about seven years old, and has successfully configured tens of thousands of hosting servers in that time, and Postfix was the MTA of choice on most of them. It has been considered "stable" by us for about five years. The core on which Virtualmin is built, Webmin, is over a dozen years old and is running on millions of servers, and has been considered stable for about 10 years.

If the installation completed successfully (with no WARN or FATAL) errors, then mail should have worked right after installation. Though, it is also possible to break the install by not having a fully qualified domain name that resolves.

In this case, I don't recall seeing this particular aliases.db error in any specific circumstance. I'm guessing Postfix was already installed and running, and perhaps didn't get restarted after the installation. I'm pretty sure Postfix would be restarted during a normal installation, but if the install bailed before completing, that wouldn't have happened (and there would have been some kind of error, though the output of and the packages it installs is a bit verbose and it might have been buried amongst other less important messages).

How much memory does your system have? Now that I think of it, I'm pretty sure the most common source of "mail didn't get configured" or "postfix is emitting odd errors during installation" is running out of memory. On a 64 bit system, in particular, memory usage can be pretty big during the install (though it doesn't actually need as much to operate afterward).

thanks for detailed reply. I would love to be able to leave plesk for an alternative. The host is and resolves correctly. I can log in and read the email folders in Thunderbird, but it won't accept an outgoing (ie sending) connection from Thunderbird. There were no error messages on install but because I am evaluating, I install on a 256meg of ram instance in the cloud. If you email me at I will reply with root login credentials and virtualmin credentials

Fixed now .. the cause was the system's hostname being the same as the domain email was sent to. Changing the hostname fixed it.

Automatically closed -- issue fixed for 2 weeks with no activity.

Hi there,

I get the message

(The server responded: " Recipient address rejected: User unknown in virtual mailbox table")

when sending from my email server (Postfix under Plesk)

If I send email to the address from my hotmail or gmail accounts, the message gets delivered. My first thought was greylisting but it is not installed.

Any ideas?

It sounds when you ran into this issue previously, it was an issue with the server name... Jamie corrected the issue by changing that name.

Is it possible the server name is back to what it had been?

What do you get when typing the command "hostname"?