Method 1:
Compress the file(s) using s/w like 7-Zip (.7z) and mail them. (Working like a charm as I tested it personally!)
For Linux users, 7-Zip has no GUI. You need not read the man pages of 7z command.
Please visit http://www.howtoadvice.com/7zipHelper
It’s a simple form that you can fill out to generate 7z commands.
You can copy these commands directly into your terminal at the command prompt.
Method 2:
Change the extension of .exe file (to an unblocked extension) and mail it.
Inform the destination person to change the extension after downloading it.
(It may not work always but you can give a shot).
Which file types can I not send or receive?
"ade", "adp", "bat", "chm", "cmd", "com", "cpl", "exe",
"hta", "ins", "isp", "jse", "lib", "mde", "msc", "msp",
"mst", "pif", "scr", "sct", "shb", "sys", "vb", "vbe",
"vbs", "vxd", "wsc", "wsf", "wsh" 
Gmail won't accept these types of files even if they are sent in a zipped (.zip, .tar, .tgz, .taz, .z, .gz, .rar) format.
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