Have had the following error message sent to me (I am set up as the root alias). Please note I have amended the domain name to WEBDOMAIN and the email addressee to USERNAME:

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This is the Postfix program at host localhost.WEBDOMAIN.org.uk.

I'm sorry to have to inform you that your message could not be 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 Postfix program

<USERNAME@tiscali.co.uk>: host mx2.uk.tiscali.com[212.74.100.148] said:
553 <apache@localhost.WEBDOMAIN.org.uk> unable to verify address (in reply
to MAIL FROM comman

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Any suggestions greatly recived. Unfortunate I am very new to Linux although I think this will chnage very quickly!!