Email is becoming a tool with diminishing value. It isn’t going away anytime soon but it has problems. Personally I get over a thousand emails a day; 90% of them offer either Viagra, millions of dollars from a deceased African politician or offers of friendship from a Russian girl who can help me fill my free time (one of these certainly interests me…).
In addition to the spam there’s also the issue of sending large files (and by large I mean more than 2MB). I don’t think there will ever be perfect spam solution but for the second issue there is an answer; Dropbox.
Dropbox allows you to send files for free. Simply download the program (free), create your account (free) then select the amount of disk space you want. 2GB is free, 50GB is $9.99 a month and $100GB is $19.99 a month. 2GB should be enough for nearly everyone.

Dropbox then adds a special folder to your computer. You simply drop files in the folder and they are instantly available on any of your other computers and the web.
When you right click on a file in the ‘public’ folder you can identify a unique Website address (URL) that allows anyone to access the file on the Web. As an example the following link is a 10MB file of an interview I did with Bernice Ross (download time is dependent on the speed of your internet connection).
Emailing this size file isn’t normally wise but emailing a link to it is. Obviously you could use this mechanism for any type of file including Office documents (Excel, Word etc) and PDF’s.