If you are filing as Married Filing Separate, you cannot e-file if you do not have your husband's SSN. No one here can get his SSN for you. If you have joint returns from prior year filings, you can look on those returns for his SSN. Otherwise, you would need to ask him.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**