I have not seen this on any org. It always create incident with default status which is "OPENED" Status . Do you have any workflow on mail listen rules?
I agree with Kedar. Probably a worflow that is setting this status.
Please check the workflow field update action and filter by field to update. set the column so you see Field to update and search for Incident; Template name.
The only way to update status is with a template (is this set in your ticket? Do you see a template?), or a custom trigger, a with flow.
Ok I am going to recheck workflow rules and triggers.
Resolved, Yes it was a workflow rule I created with a template behind the rule to update the status to In Progress that was to blame. The rule is only suppose to change the case to in progress when it meets the critieria of having a priority assigned and it works except when the incident is created by email it seems to meet the criteria even when priority is still empty. Anyhow no further tips needed I'll tweek the work rules to get this doing what I need.