Requirement to Maintain Hazard Insurance Letter

In the past we sent a letter annually to our mortgage customers regarding their requirement to maintain hazard insurance on the property they have pledged as collateral. We wanted to check to see if this is still something we need to be sending out each year or if this is something we can do away with? We do now have the Mortgage Blanket policy which covers all collateral including commercial property for hazard insurance. We understand this annual letter is not a Federal regulation, but want to verify it is not required by IN?