Royal Mail (RMG.L) announced on Thursday that it plans to increase its use of drone deliveries over the next three years as it creates 50 new "postal drone routes".
The company wants to deploy 200 drones to deliver mail across the UK over the next three years, with plans to expand its fleet to 500 longer-term.
Royal Mail said the drones will help provide faster and more reliable services to remote communities, with the Isles of Scilly, Shetland Islands, Orkney Islands and the Hebrides first in line.
Deliveries to these areas currently use regular aircraft, ferries, and land transport, but can be affected by bad weather.
The twin-engined drones have a 10-metre wingspan, which allows them to fly in difficult weather conditions.
Shares in the company were down 1.7% in afternoon trade on Thursday in London.
The services are in partnership with drone firm Windracers and subject to Civil Aviation Authority approval.
Using the drones will also help cut carbon emissions, according to Royal Mail CEO Simon Thompson.
"On time delivery regardless of our customers location or the weather, whilst protecting our environment is our goal," Thompson said. "Even though we go everywhere, Royal Mail already has the lowest CO2 emissions per parcel delivered, this initiative will help reduce our emissions even further."
Royal Mail has already conducted four trials over the last 18 months, including flights on the Isle of Mull in Scotland, the Isles of Scilly off the Cornish coast and between Kirkwall and North Ronaldsay on the Orkney Islands.
Test flights for the new service have been held between Tingwall Airport in Lerwick and Unst, a 50-mile flight each way, Britain’s most northerly inhabited island.
Drones used in the trial can carry up to 100kg of mail per trip, with letters and parcels to be delivered by the local postman or woman.
Watch: Royal Mail reveals plans for 50 new postal drone routes