Anyone expecting a Christmas parcel or card from Canada or Australia will now have to wait until the end of the month or early in the New Year to receive their mail.
Weather is being blamed for the delay in deliveries of some 10,000 items from Canada Post who have informed An Post of the delays for postage from the Toronto and Ottawa areas.
A spokeswoman for An Post said they had received notification from the Canadian postal service that due to extreme weather conditions in those regions, 10,000 items for Ireland had yet to be despatched, even though they were posted a week ago.
"It will be early in the New Year before they get them to us," the spokeswoman said, adding that they would be sorted and delivered in Ireland as soon as they were received.
Toronto and the surrounding areas have regular and heavy snowfalls at this time of year.
Australia Post has also notified An Post of a delay in some 7,000 items coming from Down Under.
The post from Australia is routed through Britain and it is now not expected in Ireland until the end of December.
An Post's spokeswoman said the company wanted to alert customers in advance in case they thought post they were expecting had gone missing.
Final post before Christmas will be delivered today and the service takes a three day break. Postal deliveries resume on Friday and post offices will also reopen that day.
