What is the SQL Server password policy feature?
Password policy is a feature introduced in SQL Server 2005 for the purpose of strengthening SQL Authentication by having it enforce the same password policies that Windows is set to enforce. This means password policy is specific to SQL logins. A password policy determines what passwords are acceptable and also when they expire or whether the account should be locked out after a number of unsuccessful login attempts due to the use of incorrect passwords. While the primary use of password policy is to strengthen SQL Authentication, password policy is also enforced whenever setting a new password with the encryption features introduced in SQL Server 2005 – this enforcement only refers to password strength; there is no expiration/lock out enforcement for these passwords. This enforcement cannot be disabled.
