Problems emailing to S60 mobile

I tried emailing a document from Zoho writer to my mobile (N95 which in theory can display it). To do this, I tried using my network supplied email account (Orange in uk). The problem: the mail arrives but without the attachment. However, I also have web access to this account (the mobile uses POP) and on the web the attachment is there.

If I export the document to a local disk and then use yahoo mail to send it to my Orange a/c, that works.

Implication (or so I guess): there is something different about the way zoho mails the document compared with yahoo.

To get this sorted out, it would help to know about any differences.

Any suggestions?