Royal Mail made 93 per cent of its first class deliveries on time in South Yorkshire between April and September.
Postal workers aim to get all first class deliveries out the day after they are posted.
Doug Neal, Royal Mail Delivery director for the Sheffield area, said: “Royal Mail’s target for next-day delivery of first class mail is one of the most demanding quality of service targets in the whole of Europe.
“We are extremely pleased that we are delivering a high quality service for our customers.
“It’s down to our local postmen and women, out on their routes six days a week, who are determined to deliver the best possible service.”
The figures were based on over 130,000 sample letters, parcels and packets sent to over 5,400 addresses.