Error when trying to send from Excel

I’m having the following error when trying to send from within Excel 97 (using Outlook 2000)…”Cannot load the mail service. Check your mail installation.”
Everything is fine when sending from Word (although the additional option to send via Mail from Microsoft Outlook is missing). I’ve re-installed Office 97 but to no avail. Outlook 2000 was recently re-installed by someone else but has not seemed to make any difference. I know there is a TechNet Q296412 article pointing out a similar problem but wondered if anyone knew of a quick fix.

Many thanks.