User Locked
A user accounts gets locked if a user enters incorrect password more than X number of times (X can be configured). 
A locked user can be unlocked by clicking unlock in Admin > Users > Users Maintanance

Deactivate a user
To prevent a user to logon to ODSNet, the user can be set to inactive. 
To de-activate a user in SAP: 
On the contact tab in SAP, untick the Active box. 
Once transferred to ODSNet, the user will be set to Inactive on ODSNet and the user will not be able to login. 

Deactivate an Account ( SAP )
In SAP B1 it is possible to deactivate the account ( the Business Partner). - This will NOT deactivate the user or account on ODSNet. To deactivate a user on ODSNet, see above. 

If the customer account is made inactive in SAP, the Web User can still logon to the ecom site and place an order. The order can not be transferred to SAP and will remain in Monitor Data Exchange in status Failed. 

The Alert notification email will alert with message: 
"Error on Order : XXXXX : DI Error: (-10) ....... - Customer ....... is inactive ...."
XXXXX is the Ecom orderid. also displayed in Monitor Data Exchange (select Export Sales order in the drop down). 

Change ODSNet userid
ODSNet use the SAP contact's email address as the userid. 
If you change the contacts email address in SAP, it will automatically update in ODSNet. 

IMPORTANT: The Email address must be unique. 
If the same email address is user for multiple accounts in SAP, the Account which is processed last will be linked to the email address.