Royal Mail has issued guidance to dog owners to protect their postal workers from attacks.
Between April 2015 and March 2016, 116 postmen and postwomen were assaulted by dogs as they tried to deliver mail.
While the number of dog attacks has fallen in Essex since 2013, they are the most common cause of assaults on postal workers.
Despite the fall, attacks on Royal Mail staff across the county account for 4.5 per cent of the national figure, with 2,600 attacks taking place across the UK last year.
The number of attacks in Chelmsford has fallen from 50 in 2013 to 25 in 2016, but the city still has the highest number of attacks in Essex.
Both Chelmsford and Ipswich had the highest number of dog attacks in 2015 to 2016, with 25 reported in each area.
In Southend, the number of dog attacks on postal workers has fallen from 43 in 2013 to 21 in 2016.
The smallest reduction has been in Romford, which had 26 attacks in 2013 down to 20 in 2016.
As many as seven postmen and women a day are attacked across the country, but this rises by 10 per cent during the school holidays and in the summer.
Royal Mail spokesperson Sally Hopkins said: "We know that the overwhelming majority of dogs are friendly most of the time, however, even the most placid animal will defend itself if it feels its territory is being threatened.
"Our first priority as an employer is to ensure the welfare and safety of our people who provide a valuable service to our customers.
"Our postmen and women deliver to over 29 million addresses across the country. We ask them to exercise caution and respect for all family members, including pets when delivering the mail. We also appeal to dog owners and their families to help reduce the numbers of attacks, particularly at the door or in the garden."
Top tips for dog owners
Ensure your dog is out of the way before the postman or woman arrives
Place your pet in the back garden or a faraway room
If you have a back garden, please close off the access, in case your dog could get round to the front when the postman calls
Dog attacks can happen when you've opened the door to sign for an item
Please keep your dog in another room before answering the door and make sure children don't open the door, as dogs can push by them and attack
Give your dog some food or a toy to occupy them while your mail is being delivered
Wait 10 minutes after your mail has arrived to let your pet back into your hallway. Keep everything as calm and low-key as possible
If your dog likes to attack your mail consider installing a wire letter receptacle. It will protect your post, and your postman's fingers
If it's not practical for you to keep your dog away from a postman delivering your mail, please consider fitting a secure mailbox on the edge of your property
Ensure your dog is microchipped, wearing a collar and tag and that your contact details on the tag and microchip are up to date