Is this grammar is correct Sir I have mailed you the scanned documents?

The grammar is not quite correct. Here's a better way to phrase it:

"Sir, I have emailed you the scanned documents."

Here's why:

* "Mailed" is generally used for physical letters or packages. "Emailed" is more appropriate for digital documents.

* "Sir" is a formal address. If you have a more specific title (Mr., Dr., etc.), it's best to use that.

Here are some other variations that you could use:

* "I have sent you the scanned documents via email."

* "Please find the scanned documents attached." (If the documents are attached to the email)