The number of attempts to login to the default Admin account on our Zimbra has increased dramatically in recent weeks.
As a result (we have a five attempt lockout policy), our Admin account keeps getting locked out.
Any way to either:
1) Disable the default domain so that they would need the valid full <admin@domain> information before triggering the lockout.
2) Rename the Admin user (not sure if this breaks things in Zimbra)
3) Have a way to block dictionary attacks?