Q: What to do if your manuscript is rejected on the grounds that it is not appropriate?

This is how the manuscript screening process works at journals. Once your paper is submitted, it is assigned to an editor who conducts an initial evaluation to see if the manuscript matches the scope and quality standards of the journal. If the manuscript clears the initial screening, it is sent for peer review; else, it is rejected.

Often, a rejection without peer review occurs because the paper is not suitable for the journal in terms of scope, target audience, etc. In your case, what the journal means is that the manuscript is not appropriate for publishing in this journal because of one of these reasons. The rejection probably indicates that your journal selection was not appropriate. This is apart of the journal publication process, and everyone faces rejection at some point of time. Don't worry, just be more careful while selecting your target journal next time.

Recommended reading:

• See how easily you can select a target journal for your manuscript
• Selecting a suitable target journal for your manuscript