Web based emails not sending to external (not local) host - please help

[mike0c]

I'm running Plesk 8 with Mail Enable standard, we have a web site with the emails hosted externally. I've modified the DNS (MX record) and the site and emails work fine, on the whole.

The only issue is with web based emails, sent from the server, they don't get sent to the external host, I get the following error:

Persits.MailSender.4 error '800a0006'

550 Requested action not taken: mailbox unavailable or not local

/routines/inc-comm-routines.asp, line 175


How can we configure the server to not see the emails as being locally hosted, but treated as an external host?

Any advice much appreciated.

Cheers
Mike