Uanble to get Windows live mail 2011 working with non-plusnet email account

[#1]

I have my own domain, email was setup on Windows live mail and working before moving to PlusNet. After trying on Plusnet, Incoming mail was working but outgoing mail wasn't and figured out that it was because the SMTP server was from my previous broadband provider. Have now tried using the standard settings for the domain and both incoming and outgoing mail are not working at all. Setup another test email address through cpanel and exported the settings directly into Windows Live mail (2011) but still not working. Using these domain settings on other devices in the same network (an iPhone and iPad) with no problems so can't understand why it should be different on the PC.
Can I use the plusnet smtp relay for an external domain?
Any suggestions for how to diagnose the problem further? I have also tried switching on and off the laptop firewall but no effect.

[#2]

Quote

Can I use the plusnet smtp relay for an external domain?

If you're on a PN connection you can use the relay for any email. If not on a PN connection ( e.g 3g or public wifi ) then you can still use it but you need to use authentication http://www.plus.net/support/email/setup/windows_live_mail_2011_smtp.shtml

[#3]

Thanks, unlikely to need to take the laptop away from the Plusnet connection but if I do, does authentication for the SMTP server work, given that the username and password won't be for a plusnet email address?

[#4]

You will need to use a Plusnet userid/password for authentication either the main account one of a mailbox one. They don't need to be the same ones as the email address, authentication for the smtp server is completely separate to that for the incoming server. For instance I have created a plusnet mailbox called smtp with it's own password. This is used for smtp authentication purposes on all my email accounts.