Four homes in the remote community of Altnabreac, Caithness, have had their mail deliveries suspended, after mail bosses said staff were faced with an hour-long trip to deliver letters and packages.
Residents of the historic area, which is home to Scotland's most remote rail station, now have to travel a 40 mile round trip to Halkirk to pick up their letters and parcels. It is thought that the measure will affect around 15 people living in the postcode.
This is the second time that postal services have been withdrawn from Altnabreac, with postal deliveries restored after a similar decision in 2014 was appealed by residents.
Ofcom regulations state that delivery staff should not spend more than 15 minutes in a single trip on private roads to deliver mail.
A spokeswoman for the Royal Mail said that the condition of the track to the houses had deteriorated in recent months.
She said: "Royal Mail has suspended deliveries to four addresses at KW12 at Halkirk and we are sorry for the inconvenience this causes customers.
"This step has been taken after a detailed assessment, as we believe that there is a risk of safety to our postmen and women who are delivering on private tracks off the public highway."
The spokeswoman added: "Royal Mail wants to work with the customers to find a safe and sensible solution to this suspension."
Until 2009, a Royal Mail Postbus, which carried mail and passengers, served the remote Altnabreac community.
Campaigners in Caithness and Sutherland have previously called for their postcode to be changed amid fears that they are hit with higher delivery charges because the region comes under a postcode in Kirkwall, on the island of Orkney.