Not that I'm aware of, but most email services have a size limit on how large attachments you can send/receive (typically no more than 20 mb and often quite less than that).
This shouldn't limit shouldn't make Outlook freeze but will probably stop you from sending the mail even if Outlook didn't freeze.
I know this won't fix your Outlook problem but I would suggest you use alternate means of delivering the file.
Upload it to a file hosting site like
rapidshare (or any number of similar sites), then email a download link for the file instead of the file itself. This way you won't risk the email not being delivered because the attachment is too big.