There is a better way to share your documents and files by email than by sending an attachment. The better way is to put your documents and files in the cloud and just share them with a link. The 'cloud' could be Google Drive, Dropbox, Microsoft OneDrive and others.
Thank goodness we have cloud computing these days to make it easier and better for everyone. BUT, it’s hard to break old habits, and you need to have a good concept, or mental model, of what is different.
So here are a few things to think about.
If you send a document (Word or Excel files) as a FILE attachment, then your people will have a copy that will never change. If you ever update the document you will have to send the updated version to them again. And there are multiple copies everywhere. If you send an attachment to 10 people there are 11 copies of it (including yours).
BUT, if you send the document as a LINK to your Google Docs document (or Dropbox or whatever) then they will always go to your shared file and see the most current version. There is only one and it is always updated.