Thanks for that!
I had downloaded the SME Server V5 with Service Link user guide 5.1 from the Mitel site, as a PDF file, and it is subtly different from the manual in the link you pointed me too.
In the PDF version, the available volume list illustrated explicitly shows an available volume entitled MYOB data, and I had taken that, together with the note at the bottom of the page to indicate that MYOB DID in fact work on e-smith. I had read the note to say that some programs may not work well but the certain specific nuances in MYOB allows it to work OK!
Thanks
Brian Rich