can recieve emails on new plusnet account but not send, where am I going wrong/

[#1]

I hvae just joined, set up a new e-mail address in outlook and can receive emails but not send, I get the following message
The message could not be sent. The setting for your outgoing email [SMTP] server might need to be configured. To find the server settings for '**********@talktalk.net', please contact your email service provider.
Subject 'Re: '
Server Error: 550
Server Response: 550 relay not permitted for your IP
Server: 'relay.plus.net'
Windows Live Mail Error ID: 0x800CCC79
Protocol: SMTP
Port: 25
Secure(SSL): No

[#2]

your outgoing server needs to be relay.plus.net

[#3]

checked that, that's ok, nay more ideas, thanks for your help

[#4]

When you say you have just joined.
Are you now connected to the internet via Plusnet as the error message indicates that you are still connected via TalkTalk so should be using their outgoing server

[#5]

yes that's done it, thanks for your help