My default Workgroup in the Windows domain does not equal my login Workgroup. I found that you can specify Workgroup (along with user ID) in the SMB connect to string. For example:
smb://WORKGROUP;machine.somewhere.com/Share
This works to specify
WORKGROUP for login. This can be expanded to:
smb://WORKGROUP;User@machine.somewhere.com/Share
I hope this helps! It has taken me a very long time to find this. With this, and Add to Keychain, I can now connect without entering the password! Before, since the
WORKGROUP was wrong, it prompted me for password.