I have at least one friend with a Gmail address associated with a fake name. In my contacts list, I have the correct name associated with the email address. I can then type this person's name in the recipient field and Gmail populates it appropriately. However, if I search this person's name in my email, their messages are not returned.
A workaround is to type "from:[start typing in the person's name and their email autocompletes]" and search for emails from that email address. However, this is unsatisfying if the person uses multiple email addresses, as I would have to look up each email address. Additionally, I might just type the person's name in and forget that Gmail isn't returning all messages from all of their email addresses, since some messages are returned.
Best Answer
you are correct, gmail search is limited in From: field. partial name will not return result or contact notes or other. btw, capitalization does not matter.