The 'Owned' and 'Rented' equipment policies include coverage for equipment while it is in use, storage or transit. This means that coverage does apply while the equipment is in the care and custody of courier companies like USPS, UPS, FedEx, etc. You need not purchase additional insurance with them.
Note that if damage or loss occurs while your equipment is in the care, custody and control of a courier company, you must still make a claim with the courier company in conjunction with your claim with InsureMyEquipment.com.
Please also note that you must first have the equipment in your possession for coverage to apply. This means that if you are renting or purchasing equipment that is being shipped directly to you, coverage will not apply until the equipment is in your possession for the first time. From that point onwards, equipment will be covered while in transit.