I often need to transfer files that are blocked (executables) or are too large to go through the corporate mail system and I've found a couple of tricks that help.
for executables you can rename the file, eg give it an additional extension, like ABC.EXE.TRASH. Then advise the recipient to delete the bogus extension before they run the file (they have to save it locally first). You can also try packing it into a ZIP file, though this isn't always
for overlarge files I use 7Zip ('cos ZIP compression is woeful) and create an SFX archive. Now this is an executable, and I either pack it into a ZIP file, or add a dummy extension
if that fails, you could always break it up across multiple emails - potentially painful, but a line of text on it's own is pretty innocuous - or munge the code somehow, eg adding whitespaces or substituting ~ for the i character would turn most of it into gibberish, but would be simple for anyone to reverse