Various problems culminating in not being able to send email
The problems I have had would fill quite a depressing book. We are using Ubuntu Hardy and ISPConfig - the server was spam bombed due to bad configuration and is finally up and running again. Everything is largely appearing to work fine with the exception of sending email.
I have some customers who like using Horde which we put on the server. They can use it for receiving from anywhere with no problems but can not send at all from it. Even sending to googlemail or hotmail results in an instant bounce back message as follows
This is the mail system at host xxxxx.xxxxxxx.co.uk.
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
<email@example.com>: unable to look up host hotmail.com: Name or service not known
I have browsed around to try and figure out what is wrong and am totally flumuxed. Any ideas?