Posting to a specific category "ONLY"

I’m trying to force a post to only go to the specific category requested in the subject.

When I create a category:subject “Captain Bob:Where are we now” in the email, the post is placed on “Captain Bob’s” category as expected. It also posts on the web site’s home page. If you use “Captain Bob:” as the category, I’d like to be able to isolate the post to that category. How would I do that in postie?

I’m guessing if you don’t use the “category:” the post will go to the sites home page?

Thanks!

https://wordpress.org/plugins/postie/