qmail receiving emails error

Hi,

I have problems receiving emails. I get this error message:

Hi. This is the qmail-send program at mail.boxdomain.com.
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.

<paranoix@boxdomain.com>:
can not open new email file errno=28 file=/usr/home/vpopmail/domains/boxdomain.com/paranoix/Maildir/tmp/1146658478.6519.mail.boxdomain.com,S=2849

Please advise what I should do as this is the first time I'm getting such error.

This could be a DNS error, with your own mail server unable to resolve the domain to which the email is to be sent. Check that your DNS server is working i.e make sure your /etc/resolv.conf either points to your local DNS server, or that you're ISP dns server is working.

It could also be generated by the remote mail server, perhaps the user is not available. Check the address that you're sending too - it could be that the user may have been deleted or you may have made a simple typo with the email address.