To configure Attachment compliance settings for your domain or organizational unit:


1. Sign in to the Google Admin console.


2. From the dashboard, go to Google Apps > Gmail > Advanced settings.


3. Scroll down to the Attachment compliance section:
If the setting's status is
Not configured yet, click Configure (the "Add setting" dialog box displays).
If the setting's status is
Locally applied, click Edit to edit an existing setting (the "Edit setting" dialog box displays), or click Add another to add a new setting (the "Add setting" dialog box displays).


4. Email Messages to be Effected.(Select one)
Inbound—Messages received by your users from senders outside the set of domains associated with your company or organization
Outbound—Messages sent by your users to recipients outside the set of domains associated with your company or organization
Internal - sending—Messages sent by your users to recipients within the set of domains associated with your company or organization
Internal - receiving—Me


5. Click Add to add an expression. (You can add several expressions to one attachment compliance setting.) For each expression:

Select File type from the drop-down list (displayed by default), and choose the attachment types to include. This expression looks for a match on attachments of specific types; for example, Office documents, Video and multimedia, Music and sound, Images, and Compressed files and archives (both encrypted and not encrypted).
For a list of file extensions that are classified in each file type, see File types and file extensions. (Note: For your protection, all executables are automatically rejected.)

You can also enter Custom file types to look for matches on specific file extensions; for example, exe, bat, and cmd. Enter one or more file extensions, without a period, and separate your entries by commas. Click Save.

Select File name and enter an attachment name that you want to include. This expression looks for a match on any part of an attachment file name; it need not match the entire name. (Case is ignored.) ClickSave.


Select Message size and enter the number of megabytes to limit the size of messages (Ex.5 Mb). Click Save.


6.  If above expression matches This section enables you to specify action to be perform. You have two       options in the drop-down menu: Reject message or Modify message.
Reject message This option rejects the message before it reaches the intended recipient. You can then enter customized text for the rejection notice.
OR
Modify message This option enables you to modify messages by adding headers, changing the route, changing the envelope recipient, adding more recipients (additional, or secondary routes), and removing attachments.

 

7. When you're finished with your changes, click Add setting or Save to close the dialog box.
Note: Any settings you add will be highlighted on the "Email settings" page.

 

8. Click Save changes.