How to: Attach a file from OneDrive for Business to an email message in Android

1) Long press the file you wish to attach to the email message. Then, tap the Share icon at the top.

TIP: You can tap more items to select them before tapping the "Share" icon at the top.

example screenshot

2) Choose the mail app that you wish to use for sending the file.

NOTE: The example screenshot uses Outlook, but you can use any email app that is available on your device.

example screenshot

OUTCOME

You have attached your file from OneDrive for Business to an email message.