>>>Hi,
>>>
>>>I am testing access to a new customer database (not the first time a very similar environment). What happens is when I use Windows authentication (specify in the connection string IntegratedSecurity True) connection works. But when I try SQL Server authentication I get connection error (basically connection denied). For SQL Server authentication I created login and then in the database I created user of the same name. The user has roles: db_datareader, db_datawriter, db_owner. But nothing works. I have double checked the password (I made it very simple 'test') but can't make the SQL Server authentication to work.
>>>What could be missing? TIA.
>>
>>Could you connect with SSMS using this login?
>
>No. I get error "Cannot connect to SERVERNAME" What could it tell me? Thank you

Connect with SSMS using Windows authentication. Right click on this login and "Properties->Status"
Also make sure that this login has rights on master DB.