You can put the file on a file sharing site (there are many) and provide a link to it in a message.
[There may be a lower limit of the number of posts you need to have posted here before you can include links here - I'm not sure. At several forums it's 5 posts minimum - so if you come across this, just add sufficient short posts or include the link but miss off the https: or http: from the beginning of the link so that the system here doesn't recognise it as a link]