For a better way to transfer large files, we recommend using online services like Google Drive, Dropbox, etc. or using FTP. Email is not an ideal solution for transferring large files, due to limiting file sizes across various email servers and networks.
It is important to realize that email was not designed for sending and receiving files. The limit for our POP email on total size per email message is 5MB (including header, message body, and attachments), which is still a significant size that will allow you to send files such as documents and images.
If you need to send or receive a larger file or program, we suggest using FTP. You may setup an individual FTP user with restricted access if necessary. Learn more about FTP here.