Evidently, Dolly Lester was a conscientious youngster. One of 12 children, she lived with her family at Farfield Cottages, Addingham – her father, George, was Samuel Cunliffe Lister’s chauffeur – and wrote to First World War soldiers.

More than that, she knitted socks for them and sent them packets of cigarettes, according to her niece Mrs Jean Butler, of Wrose.

The correspondence appears to have been initiated through an organisational intermediary, a Mr C Flint, but Mrs Butler does not know who he was; nor do any of her Aunt Dolly’s letter-writers say.

One letter, from Lance Corporal A Watts, dated January 30, 1916, states: “Mr Flint tells me that you are working very hard for the Boys from the old village (Addingham) who are serving there (sic) country out here and I am sure they all highly appreciate whatever you all do for them, although we do not fare so badly under the circumstances...”

Flint’s name occurs again in a letter from Harry Driver who wrote: “No doubt you will be surprised to hear from me, and are wondering how I got your address. Well, Mr Flint sent me your address in his last letter. He also told me of your splendid work in allocating money for his fund...

“It gives me the greatest pleasure to know that we are not forgotten by the people of Addingham. It is splendid to think that even a little girl of your age can do her ‘Little Bit’ and by so doing help to make our lives a little bit brighter during this trying ordeal.”

On the eve of the first battle on the Somme in France, in which the British Army suffered nearly 60,000 casualties on the first day, Corporal B Atkinson (5568), a gunner with the 19th Siege Battery, wrote from France to Dolly Lester.

“I am at present away from the firing line about 15 miles, on the ammunition column where we have to load up the shells and other things that are required for the guns and it is quite a change to get away a bit, it breaks the monotony.

“The villages here are all mining villages and it (is) quite a treat to see all the houses standing as where we have been they are all battered by shell fire and you would have a job to find one that is not damaged in some way or other...

“It is a shame when you get further up and see the damage and destruction that the Germans have done but they have to pay for it in the end as we shall beat them and they will be sorry that they started the war at all.

“In some of the villages you see both woman and children living there and they get shelled every day and are running the same risks as the soldiers themselves and it is a shame that the authorities do not remove them to a place of safety.”

One letter sent on February 17, 1916, came from an Australian stretcher-bearer, Private Harry Emmott, recuperating in Egypt. After saying he was sorry for, in the circumstances, not being able to send much news, he said:- “But I am enjoying a rest after the fighting on Galliopoli. When I go into Cairo again, I will get a few post cards to send you for your album. You will no doubt find them very interesting.”

Private Emmott ended by saying he hoped to come home soon and that Dolly’s family were enjoying “grand health”.

Of the eight letters supplied to us by Mrs Butler, three of them had distinctive green “honour” envelopes, faded over the course of nearly 100 years. All are marked ON ACTIVE SERVICE and bear the marginal note: “Correspondence in this envelope need not be censored Regimentally. The Contents are liable to examination at Base. The following Certificate must be signed by the writer: ‘I certify that on my honour the contents of this envelope refer to nothing but private and family matters’.”

Four of the remaining five plain envelopes all bear the red triangular stamp of the censor and the black circular stamp of the field post office.

All these letters passed through the General Post Office, as it was then called. Throughout the 1914-18 War the GPO delivered up to 12 million letters a week to soldiers, irrespective of whether they were training somewhere in England or facing the enemy somewhere in France, Belgium, Turkey or the Middle East.

The snow storm of correspondence reportedly started in 1915 when a soldier on the Western Front wrote to a London newspaper saying he felt lonely and would welcome some friendly correspondence.

The newspaper published his name and regiment and within a matter of weeks he was lonely no more: he had received more than 3,000 letters, 98 large parcels and three mailbags full of smaller packages.

The GPO was already a formidably large and powerful organisation before 1914, employing more than 250,000 people and with annual revenue of £32m. The cost of a stamp was just a penny – as it had been for 70 years.

From 1915 onwards, the GPO had to deal with an extra 12 million letters and a million parcels sent to soldiers each week.

Another 35,000 temporary workers, mostly women, were hired, in part to handle the extra business and in part to make up the numbers after 12,000 GPO male staff joined the Post Office Rifles.

According to the British Postal Museum & Archive in London, 1,800 volunteers were killed and about 4,500 were wounded.

At the outbreak of war, the GPO built a large wooden temporary sorting office covering five acres of Regents Park which by 1918 employed more than 2,500 mainly female staff. All mails bound for troops on the Western Front were sorted at the London Home Depot, as the place was called.

Bags of sorted and censored military mail were transported by three-tonne Army lorries to Folkestone or Southampton where ships delivered it to Army Postal Service depots in Le Havre, Boulogne and Calais. In 1917 more than 19,000 bags of mail were leaving England for France every day.

Trains dropped off the mail at railheads behind the front lines where it was collected by Royal Engineer Postal Section lorries and taken forward. Roadside regimental post orderlies sorted it and cartloads were wheeled to the trenches for delivery To young Dolly Lester in Addingham and the soldiers she wrote to abroad, the vast organisation that received and delivered their letters was largely invisible. But it seems to have worked amazingly well.

The men of the Post Office Rifles who were either killed or wounded were not the only GPO casualties of the war. Before 1914, young Walter Midgley from Bradford worked as a messenger for the Post Office.

He was a private in the 1/6th Battalion, West Yorkshire Regiment, and was killed on November 19, 1915, in France. In a T&A spread on March 26 this year, his nephew Martin Midgley wondered whether his uncle had been a member of a GPO band before joining up.

We’ve had a letter from Mrs Joan Scurrah of Wellington Road, Wilsden who said her father, Walter Pickersgill, was also a messenger in the Post office probably at the same time as Walter Midgley.

She said: “There definitely was a band as my grandad was a member of it. My father would have liked to but was not allowed to as he was told there were a ‘boozy lot’.

“My uncle Henry was also in the Post Office. It seemed to be a family tradition as both my sister and I became Post Office employees as telephonist and telegraphist respectively.

“Regarding Walter Midgley, I wonder if Martin knows that there used to be a memorial plaque in the head office in Forster Square commemorating Post office employees who were killed in the Great War?

“Every November 11, a wreath used to be place under it. On one occasion, I had to undertake the task. My father was a staunch British legion member and was the instigator in forming the Bradford Post Office branch of it.”

Mrs Scurrah does not know what happened to the plaque when the building was taken over by Bradford Cathedral to become St Peter’s House, a museum of religion. It was taken over in 2007 by the South Asian arts group Kala Sangham.

One consequence of World War One was the price of a postage stamp. The standard postal charge for letters had remained a penny for 75 years. On June 1918, the price of a stamp went up by a halfpenny.