On a repo with email already set up and working, you can see this with:

1. `fossil unset email-send-command`
2. Go to Admin → Notification and click the "Apply Changes" button.

This should set this attribute to the default, "`sendmail -t`", but it doesn't. You can double-check it by enabling `admin-log` and clicking the button again, showing that it doesn't get into the `if` test within `entry_attribute`.

To get this settings change to stick, you have to change that input field to some other value, apply the change, then change it back, and re-apply it.

If you use your browser's developer tools to inspect the POST parameters, you'll see that `ecmd` is being sent, regardless of field contents. That means the `if` shouldn't be skipped due to the `zQ` test: `P("ecmd")` should be returning a nonzero pointer.

I've tried to debug it, but I got lost trying to figure out how Fossil processes an HTTP POST.