Postal workers are refusing to deliver mail to a street in case they are attacked by gulls.
Royal Mail said the "frightening attacks" from nesting birds resulted in deliveries being suspended to some addresses in Liskey Hill Crescent, in Perranporth, Cornwall.
It said postal workers experienced swooping attacks from the aggressive gulls which are thought to be protecting their chicks.
The Royal Mail apologised to those affected and said residents can collect their mail from a nearby post office.
Val Bodden, from Royal Mail, said: "The regular postwoman delivering to addresses in Liskey Hill Crescent, in Perranporth, has been experiencing swooping attacks by seagulls as she delivered her round over the past few weeks.
"The safety of our people is paramount to Royal Mail and these swooping attacks have made it difficult for her to continue to do her job.
"Unfortunately these frightening attacks have meant that this week we have temporarily suspended deliveries to some addresses in Liskey Hill Crescent.
"These kinds of attacks do occur at this time of year across the country as gulls are nesting.
"We apologise to those customers affected and we will resume deliveries as soon as it is safe for us to do so and we are continuing to monitor the situation.
"Customers affected have been written to and we have advised them that they can collect their mail from the local post office a few hundred yards away in St Pirans Road, Perranporth."