d. If a mortgagee or lienor has registered with the department pursuant to the provisions of section 27-2109 of article two of this subchapter, any notice of violation or other notice, or any order authorized or required to be served by the department under the provisions of this code on the owner of a dwelling may also be mailed to such mortgagee or lienor no later than five days after the date upon which such notice or order is served upon the owner, but the department's failure to mail such notice or order to such mortgagee or lienor shall not in any way affect the validity of service of such notice or order upon the owner.