This is a similar question to How do I avoid the server-specified security policies for my work e-mail? but whereas they are trying to use an Exchange email account without accepting the server's stringent security policies, I'm trying to cancel setup of the account.
The problem is, I can't open my Mail app without accepting these security policies. I get a dialog:
[Server] requires that you update your security settings
...with two options - accept the security policies, or cancel, which simply closes the app.
How can I remove this half-complete Exchange account from my Mail app, when the Mail app won't open without accepting the policies and completing the setup of the account I no longer want to set up?
I'm on Android 5.0.2, non-root.