Here is a method for scanning to email on Windows 10 that will work with any scanner or email account, even Gmail.

Generally I like to train people to use the gmail.com web interface as it gives the best email protection and productivity enhancements like Smart Compose.
But some people prefer an easier method for attaching scanned documents to an email. Locating the scanned document (navigating a file system) is often the area that people become unstuck.

The following Setup and How To is for those scenarios you are unable to train the user to use Gmail for sending attachments.

Setup

These setup steps must be completed once before this method will work. 

Get Windows Scan - Microsoft Store

Get the free app Windows Scan from the Microsoft Store.

Set Window Scan file type to pdf

Open Windows Scan and in the left column change File type from png to pdf.

Add your email account to Mail in Windows 10

This method requires using Windows 10 Mail. I'm not a fan of Windows 10 Mail except it is useful in this case. For everyday gmail usage, continue using the gmail.com web interface

Follow this link: Add email account to Windows 10 Mail

Set Microsoft Edge as default pdf handler

Out of the box Windows 10 sets Microsoft Edge as your default PDF reader. If you've been using another software to handle this type of document, you can quickly set Edge as your preferred PDF reader.

Go to Settings > Apps > Default apps, click the Choose default apps by file type link. Then scroll down and click the app that is currently set a default for .pdf, and select Microsoft Edge from the list.

Set Mail as default email client on Windows 10

This is required so we can send the scanned pdf as an email attachment, directly from Edge.

1. Click on the Start Menu  button bottom-left.
2. Now click on the Settings  menu item.
3. Then click the System  icon.
4. Click Default apps.
5. Under for the Email heading, click on current default email client.
6. In the Choose an app menu, click Mail to make it the default app.

How to: Scan to email from Windows 10

Now with Setup complete, we scan to email from the computer using this method.

1. Open Windows Scan, also known as Scan.
2. Click Scan to start the scan.
3. Click View to open. We're expecting the pdf to open in Edge.
4. Click Share.  
5. Click Email. 
6. Choose account to send from, if you have more than one email account.
7. Enter the recipient in the To field. 
   You may like to change the subject and write a message so that person knows what this attachment is about.
8. Click Send.

More resources

• Send attachments with your Gmail message. This uses the Gmail web interface for sending attachments, or you can share from Google Drive.
• Microsoft Outlook and the free email client Mozilla's Thunderbird are alternative email clients for sending files as an attachment. Can work with the Right click > send to mail recipient.
• The scanner might have an inbuilt Scan to Email function using the touch screen or buttons on the scanner / multifunctional printer.