[cyberfreak95]

This utility was exactly what i need to find the key with reg logger...

So if anyone's interested the Registry key to change the font size is:

HKCU\Software\Microsoft\Inbox\Settings\Zoom

It's a DWORD that can be configured between 1-4 depending on how big you like you Conversation text. 1 is the smallest.

Thanks for all the great work on all the little utilities and help!