UBB.Developers Forums UBB.threads 7 Development How Do I? Password mails disappears

I run 6.4.1 on a new server. Forums seems to work great, and the server is really fast

But lots of user password mail don´t seem to be deliverd. Same with mail from the contact form. I found some returns when I loged in as root via ssh ant then enters mail. It says that my main adress is unknown.

Sending mail to users from admin section don´t work either.

Any idea on where to loook for errors?

The problem seems to be this:

The server don´t recognise the from address, and the letters are held up in the mailque with the status "Deferred: 450 : Sender address rejected: Domain not found".

My mail is normaly hosted on another server, but should that be a problem?

Anyone who knows how to fix this?

Do you use sendmail or smtp to send the mails?
It's a config option in your php.ini.

I use sendmail.

Where in threads do I specify the path to sendmail? My phpinfo-page say it´s:
/usr/sbin/sendmail -t -i

Sounds right?