How to fully remove and reinstall the mail app?

I really don’t understand, I have done:

DELETE FROM `oc_migrations` WHERE app='mail';
DELETE FROM `oc_preferences` WHERE appid='mail';

drop table oc_mail_accounts;
drop table oc_mail_attachments;
drop table oc_mail_aliases;
drop table oc_mail_coll_addresses;
drop table oc_mail_mailboxes;

and still when I re-download and enable the mail app this is what i see:

and no way to delete it or change its settings.

Originally before i upgraded to 17 i had auto mail accounts installed, but now it is removed and its config removed from config.php

How do i completely erase this account?