Open eMailSignature > Configuration, Database:
- Database = emailsignature
- Username = emailsignature_superuser
- Password = changemenow
If you get an error when trying to connect to the database using the built-in SQL Server login and user, your SQL Server Database Engine is set to Windows Authentication mode during installation. If that is the case, make sure that either permissions for Integrated Authentication are set up, or change SQL Server Authentication to mixed mode.