"User unknown in virtual alias table" when send form on website

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#1 Thu, 05/19/2016 - 12:48

"User unknown in virtual alias table" when send form on website


One of my websites has a weird problem sending a contactform, when I migrate this website from a ubuntu server to a centos (6.x) server. A message send with the form of his website does not receive the external mailserver.
Yes, I use Virtualmin, without mail, which is running on a external server. I have Postfix running for website forms and within Ubuntu is worked fine, but it doesn't in Centos. The strange thing is dat joomla! and wordpress forms working OK, but this one not.

This is the mail system at host vm3.hostingserver.com.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

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

The mail system

<info@client-emailadres.com>: User unknown in virtual alias table

I think it is an internal error of postfix, but how can I get postfix running to the info@client-emailadres.com, which is running outside the webserver?

Please help

Kind regards,


Thu, 05/19/2016 - 21:40


If email is being hosted at an external mail server, you'd want to make sure that the Mail for Domain feature is disabled, otherwise it would try to deliver email locally.


Fri, 05/20/2016 - 00:52

Hi Eric,

Thank's for your answer. I also thought that it has something to do with trying deliver locally to a not existing adress.

But mail for Domain is general unmarked in Virtualmin -> Features and Plugins. In the colum 'domains' it gives the number 0. I have unmarked this feature by al my hostingservers when I configure them.

Is there another way I can check that this specific domain has forced another setting, e-mail related, when I migrated it?

I mean, when I migrated (backup & restored with virtualmin) this domain from ubuntu to centos the only thing I ignored was indeed 'mail for domain'. But that is common in my situation, because this text is also appearing when I restore a backup from the same server. So I allways mark that to ignore.

Kind regards,


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