You've told us the make of laptop, your operating system and your email provider but you've omitted to tell us which
program you're using to send and receive emails. Since it's that program which is generating the unwanted capital letters, we're left guessing as to a way forwards.
However I'll guess that you're using the Windows 10 Mail app. A quick bit of googling suggests that lots of people have experienced the same problem but, unless Microsoft have come up with a fix since the various threads have appeared online, there appears to be no way around it.
For example, Microsoft's response to the problem here was simply that "Mail app is designed to work in this way":
https://answers.microsoft.com/en-us/windows/forum/apps_windows_10-outlook_mail/windows-10-mail-app-how-to-disable-auto/af64d339-80ea-4ae4-8823-d006e10ffa5c
So it appears that your only solution might be to abandon Microsoft's own software (which is always a good idea anyway!) and to use a decent email client instead:
https://www.mozilla.org/en-GB/thunderbird/