Outlook keeps track of the files you have worked on recently and suggests them whenever you decide you want to attach a file to an email message. Some file types are blocked from being sent or received. See Blocked attachments in Outlook for the complete list.
In a new message, a reply, or a forwarded message, select Attach File from the Message ribbon or the Insert ribbon.
Select your file from one of the following locations:
Recent items
The 12 most recent files you've worked on will be displayed here. These files may be on your computer, on OneDrive, SharePoint, or another online document library. Select a file to attach it to your email.Browse Web Locations
Locations include OneDrive, SharePoint sites, or other locations such as a groups document library that you've accessed before. Select one of the locations to open a new window and then select your attachment.Browse This PC
Opens a File Explorer window where you can choose a file from your computer.
If you selected a file on your local computer or group document library, a copy of the file is attached to the email. Selecting a OneDrive or SharePoint file, however, provides you with additional permission options and information.
Send a link or send a copy Sending a link to the OneDrive or SharePoint file keeps the size of your email message small. If you choose to send a copy of the file, the entire file is attached to the email, just like it would be if you selected a file on your computer. If you choose to send a link to the file, you can also set the permissions on your file.
By default, if you're in a business environment, everyone within your organization can edit the linked file. To change these permissions, select the arrow at the right of the attachment name to display a drop-down menu with a variety of permission options.
Organization can Edit if you want anyone in your organization to be able to modify the file.
Organization can View, if you want anyone in your organization to be able to read, but not modify, the file.
Recipients can Edit if you want only the recipients of your email to be able to modify the file.
Recipients can View if you want only the recipients of your email to be able to read, but not modify, the file.
If Outlook detects that your recipients won't be able to view the file, for example if it's stored on a SharePoint site that's only accessible to you, you'll see a warning message directly under the file icon and name. Select Attach as copy to change the attachment from a linked file to a copy of the file.