Various problems culminating in not being able to send email

[cgilhooley]

Hi,

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

<xxx@hotmail.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?

Thanks

[cgilhooley]

I have solved the first problem by amending /etc/postfix/main.cf and changing the 'SMTP_HOST_LOOKUP = ' section from 'dns, native' to just be 'dns'. Now when I try to send an email to anywhere external to my server I get the following bounce back message

<xxxx@hotmail.com>: Host or domain name not found. Name service error for name=hotmail.com type=A: Host found but no data record of requested type

I have SSH's onto the server and can telnet port 25 to external sources without a problem

Anyone able to shed some light on what is wrong?

[cgilhooley]

Yeah all sorted.. Seems that DNS had gone very screwy. Simply reset it all and messages have gone away!