Search for String Literal in KQL

How do I search for a literal string value?

Current example query:
Subject : "[External Sender] Test"

Brings back what I'm looking for, but also the following:

[External Sender] test-results.pdf
[External Sender] Test - Monthly Activity CN

I would like to return only docs that has that exact subject, including case sensitivity and the special characters.

Hi @Samsquantch welcome to the community.

Perhaps, take a looks at this article

I suspect you have not defined any mappings so you are indexing both text and keywords so assuming you are using Discover your query would look like

Subject.keyword : "[External Sender] Test"