Unlike today, when we have smartphones and a host of other electronic devices to make immediate contact with people anywhere in the world, the only method soldiers had of contacting home was by letter. Home sickness was a huge problem so the soldiers were given postcards and writing paper which could be sent home for free. Most letters were read by an officer (a censor) who checked for anything that might give away army secrets. The censor also made sure that letters were not too sad, so they did not spoil the morale of people back home.
As well as letters and postcards, newspapers were also sometimes delivered to the trenches so that soldiers could keep up to date with what was happening in the war, at home and in other parts of the world.
However, the number of letters being sent became too much for the sensors to read so, in March 1915, the army introduced ‘green envelopes’. These became known as ‘honour envelopes’ as the writer had to sign that ‘on his honour’ the letters were about private and family matters only. A soldier was only allowed one green envelope per month, so they became very much in demand, with some soldiers exchanging cigarettes and other valuables for them.
Back home, the number of letters going to and coming from the trenches became so great that the Post Office had to employ many thousands of women into jobs that had only been held by men before the war. This was the first time that women were allowed to deliver post.