First of all you didn't mention the file size which you want to send. Anyhows, first of all compress it using any compression tool like WinZip or WinRar and then try it. Or even if it doesn't work, then use Google Documents and upload the file there, really its very good and nice service from Google to share your documents. Personally i recommend this service.
Types of files that you can upload:
Documents (up to 500KB)
* HTML files and plain text (.txt).
* Microsoft Word (.doc), Rich Text (.rtf), OpenDocument Text (.odt) and StarOffice (.sxw).
Presentations (up to 10MB from your computer, 2MB from the web, 500KB via email)
* Microsoft PowerPoint (.ppt, .pps).
Spreadsheets (up to 1MB)
* Comma Separated Value (.csv).
* Microsoft Excel (.xls) files and OpenDocument Spreadsheet (.ods).
PDF Files (up to 10MB from your computer, 2MB from the web)