Using MessageTag/Outlook 2007

Normal settings (for those using Telkom DSL South Africa):

Outgoing server (SMTP): smtp.saix.net
Outgoing server port: 25

To use MessageTag, a change must be made:

Outgoing server (SMTP): 127.0.0.1
Outgoing server port: 7362

This has worked OK for two years now and all of a sudden Outlook 2007 will not send emails. Is the problem with Outlook 2007 or elswhere?