I may be wrong on this one Dave, but the only way that I know around it is
to send *attachments* as a WinZip or Win Rar archive.
Should you mean that OE (and this is an Outlook group) breaks up large
*messages* then this should not be a problem for the recipent. Assuming
they too are using OE, they should just select all of the received parts,
RIGHT click on them, and select Combine and Decode. Voila!