To send files via OneDrive
Make sure the document that you’re trying to send is saved to OneDrive.
If it’s saved somewhere else, you can copy it in to a OneDrive folder:

Open the folder containing the document, right click the document and click Share

This will bring up the sharing tab.

You can simply put in the recipients email address and hit send.

There are a few other options that you might find useful that can give you more control over what your recipient can do with the document.
To access additional options, click on People you specify can edit to bring up the additional link settings menu.

In this menu you can set the following options:
Who would you like this link to work for:
Specific people: This is the default setting and means that only people who’s email addresses you’ve set can access this link. This is the most secure way to distribute a document to a specific customer.
Anyone with the link: This means that the person you send the link to can share the link with anyone they like, and anyone can access the document. This can be useful when sending marketing materials out to customers, as it allows them to easily share them with their contacts.
People in with the link: Anyone with an email address in your business will be able to access the document.
People with existing access: Anyone who already has access to the OneDrive / Sharepoint folder that the document is stored in will be able to access the document.
You can also toggle Allow Editing for documents, to prevent the person you send the document to from making changes to your copy of the file.
If you have Allow Editing switched on, you can set Open in review mode only on. This means that when the recipient opens the email, they will only be able to review the document and add comments without making any changes.
If you do not allow editing, you can also Block Download to prevent them from making their own copies.
When you’re happy with your changes, click apply to return to the send screen.
Your recipient will receive an email that looks like this

They can simply click open to launch the document.