If "Zolo Express" is the name of a company currently in business in the USA, then their business name is protected by trademark law even if they did not register the trademark with USPTO. As such, they can, if they want to, file a UDRP (cost to them is around $2K + any attorney costs) and take the domain away from you. They could even sue you in court if they believe they can prove damages and it is monetarily worth it to them.
Therefore, contacting a company to sell them their own name may prove to be a bad idea. This is considered squatting. Unless you registered your domain before they even started using the name for business, you may never win a UDRP or court case. This is especially true if you contact them to buy the domain because now they have evidence that you may have bought the domain for the specific purpose of profiting from their TM.