The number of letters delivered each day by Royal Mail has shrunk by 4 million since last year.
The drop comes as email extends its hold, and families have to contend with higher stamp prices and financial pressures.
The daily postbag contains 54 million items, down from 58 million this time last year.
The figures emerged as Royal Mail revealed its financial results for the six months to September.
They featured a turnaround from UK losses of £41m in the UK last year to operating profits of £99m this time.
The total volume of letters of the six months fell by 9%, though letter revenue was up 2% - or £44m - following April's rise in stamp prices.
First class stamps went up from 46p to 60p, second class from 36p to 50p.
As genuine letters decline, junk mail is taking over the typical postbag. Marketing mail is approaching half of all letters.
The number of unaddressed letters and fliers has actually been rising.