In a round about way... 10mb. If you need more file support,
check out a premium pay email service, or a large file support
website. Toobigforemail
Presently it's 25MB. And you can always split your files and
send them one after the next, or try making them into zips or rar.
Try searching for, "file reduction freeware." Also, look into free
FTP apps, they allow large file transfers.