A customer can enter his password incorrectly up to four times, after the fifth incorrect entry the account will be blocked automatically.
After unblocking the account via the plenigo backend, the customer can start a new login attempt. If the password is entered incorrectly again several times, the account will be blocked again.
If a customer account is blocked due to incorrect password entry, this will be displayed by an info box on the overview page of the customer account. The account can also be unblocked directly via this info box.
Fig: Blocked customer because of wrong password entry