A convert to Outlook of Mac had a question:
Outlook is inserting a period from my hitting the space bar twice. Is there a way to disable the automatic insertion of the period after hitting the space bar twice.
This behavior is a Mac feature. You can turn it off in System Preferences, Keyboard. Select Text at the top of the dialog. The Add period after double-space option is listed on the right.
I actually like this behavior, but I’m not in the habit of using double spaces at the end of a sentence. It makes sense to have it in desktops and laptops since it's common (and useful) on phones and tablets.
It's not (yet) a feature in Windows or Office for Windows and you can't add it to Autocorrect in Office. (Autocorrect won't accept only spaces.)