Hi ! This is Benpella . I'm a fellow Outlook.com user and I'm sorry to hear about the issue.
When composing an email message, you might see some symbols within your text. These are actually formatting marks, such as dots (for spaces) or arrows (for tab characters) in Outlook. Formatting marks assist with text layout. They do not appear on a printed message.
If you prefer to use keyboard shortcuts for completing tasks in Windows 10, or you simply want a way to turn off formatting marks in Outlook on the fly without navigating menus, you can also remove or add the paragraph mark and other formatting symbols by pressing Ctrl+Shift+* at the same time.
Benpella