Sending an executable file via Outlook

I was needing to send an executable file from my work e-mail to my personal e-mail. I knew that Outlook would initially try to block it, so I renamed the extension. That did not work. I then tried ZIPping the file up. That did not work. I then tried those same two things with my work's browser client. Neither worked. I tried sending the renamed file using my Hotmail account. That worked. That meant it had to be the Exchange server. I could only surmise that Exchange was examining the file's contents and determining they were unsafe. The only thing I could think of that it would be using to differentiate between my executable and some other binary was the PE section. Using Visual Studio, I changed "PE" to something else, renamed the file's extension, and sent it successfully using outlook.