Using XP and Outlook Express.

Lately, have been having problems sending large data or voice attachments to OE. OE has a feature which allows for breaking up of the attachment, by going to the Advanced tab of mail properties. One can select the break point, e.g., 60 kb or some other number. However, no suggestion is given as to what that break number should be.

What number should I select as a break point for my attachments?