Google does not allow to send mp3, videos, zip, rar files using Gmail.  But we can send jpg files freely. Because of the Google Antivirus Program.  Google is very aware about attachment and does not allow to end any zip, etc files using Gmail because of malware and viruses and security issue.

    1.   Rename the files

    2.   Winrar Tools

    3.  Using Free File hosting site like 4shared, google drive etc.

 1. Rename the Files  : Just  Change the extension of the file.  If you want to attach  apps.exe then  change the extension name i.e. apps.jpg 

By, using this simple trick, you can easily attach and send any files using gmail.

Note  :-  You have to tell your friend that when they receive your file then they will change the extension name.  For eg,  like above files, If your friends receive apps.jpg file then they have to change again extension name i.e. apps.exe   

2. Using Winrar Tool  :  Gmail does not allow us to send zip, exe files but allow us to send .rar files. So to send these files you have to compress the exe or zip files using Winrar tool in rar file  and then you will be able to attach and send these files.

3. Using Free file Hosting Service :  If you have more files to send , then you can take help of free file hosting sites like 4shared , Rapidshare, Yousendit, Google Drive,   Megaupload  etc.

 Just, Upload your  zip, exe,  videos files in these file hosting site and get the link of your file and then send the link with your Gmail message.