Apple Mail adds blank rows to CSV file

I’m having an odd problem. I’ve recently decided to try Apple Mail as my default mail platform. Everything is being great until a coworker noticed that the .csv files I send come out with blank rows in between.

• This is the original file (randomly generated for this example).
  

• This is the file sent by another mail platform (Outlook Desktop for example),
  and opened with TextEdit app or Notepad in windows.
  

• This is the file sent with Apple mail on Mac, and opened with TextEdit app or Notepad in windows.
  

I’ve been looking into resources, and apparently there is some different with formats using such as CR in Mac, and CRLF in windows but I still can’t answer this questions.

1. Why does this happen?
2. Is there a setting I can correct in Excel?
3. Is there a setting I can correct in the Mail app?
4. Will this happen with other types of files?

Any help on this is appreciated!

Note: File also has blank rows when opening in Excel, or Numbers after it was sent through Apple Mail. Before this, the file looks normal in all apps mentioned above.