This poem was written for a documentary movie, also titled Night Mail, about the London to Scotland train. As such, there's a very good video of it. From 1936.
This is the Night Mail crossing the border,
Bringing the cheque and the postal order,
Letters for the rich, letters for the poor,
The shop at the corner and the girl next door.
Pulling up Beattock, a steady climb:
The gradient's against her, but she's on time.
Thro' sparse counties she rampages,
Her driver's eye upon the gauges.
Panting up past lonely farms
Fed by the fireman's restless arms.
Striding forward along the rails
Thro' southern uplands with northern mails.
Winding up the valley to the watershed,
Thro' the heather and the weather and the dawn overhead.
Past cotton-grass and moorland boulder
Shovelling white steam over her shoulder,
Snorting noisily as she passes
Silent miles of wind-bent grasses.
Birds turn their heads as she approaches,
Stare from the bushes at her blank-faced coaches.
Sheepdogs cannot turn her course;
They slumber on with paws across.
In the farm she passes no one wakes,
But a jug in the bedroom gently shakes.
Dawn freshens, the climb is done.
Down towards Glasgow she descends
Towards the steam tugs yelping down the glade of cranes,
Towards the fields of apparatus, the furnaces
Set on the dark plain like gigantic chessmen.
All Scotland waits for her:
In the dark glens, beside the pale-green sea lochs
Men long for news.
Letters of thanks, letters from banks,
Letters of joy from the girl and the boy,
Receipted bills and invitations
To inspect new stock or visit relations,
And applications for situations
And timid lovers' declarations
And gossip, gossip from all the nations,
News circumstantial, news financial,
Letters with holiday snaps to enlarge in,
Letters with faces scrawled in the margin,
Letters from uncles, cousins, and aunts,
Letters to Scotland from the South of France,
Letters of condolence to Highlands and Lowlands
Notes from overseas to Hebrides
Written on paper of every hue,
The pink, the violet, the white and the blue,
The chatty, the catty, the boring, adoring,
The cold and official and the heart's outpouring,
Clever, stupid, short and long,
The typed and the printed and the spelt all wrong.
Thousands are still asleep
Dreaming of terrifying monsters,
Or of friendly tea beside the band at Cranston's or Crawford's:
Asleep in working Glasgow, asleep in well-set Edinburgh,
Asleep in granite Aberdeen,
They continue their dreams,
And shall wake soon and long for letters,
And none will hear the postman's knock
Without a quickening of the heart,
For who can bear to feel himself forgotten?