All postal services from the Isle of Man to Europe, Turkey and Canada have been suspended, the island's post office has said.
It comes after Royal Mail and Parcelforce announced a suspension of services to mainland Europe amid restrictions at ports due to fears about a mutant strain of coronavirus.
All international mail from the island is delivered through those operators.
Turkey and Canada mail was suspended due to a lack of available UK flights.
Postal services on the island, incoming mail from the UK, deliveries addressed to the Republic of Ireland and all other international destinations remain unaffected.
It was unclear how long the disruption would last, a post office spokeswoman said.
No new letters and parcels to the areas affected will be accepted at the island's post office counters until further notice.
General manager of mail Geoff Rickard said post for those destinations already in the system would be transported to the UK and "securely held" until it could be delivered.
The island's services had been suspended to stop any more letters and parcels adding to the backlog already being held, he added.
On Monday Royal Mail said it had temporarily suspended all mail services to Europe, with the exception of the Republic of Ireland.
A statement added: "We're additionally experiencing delays to Canada and Turkey as air capacity is severely limited."